• Journal of Sensor Science and Technology
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• v.25 no.6
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• pp.423-430
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• 2016

This study used a single metal oxide semiconductor (MOS) sensor to classify the major odorous gases hydrogen sulfide ($H_2S$), ammonia ($NH_3$) and toluene ($C_6H_5CH_3$). In order to classify these odorous substances, the voltage on the MOS sensor heater was gradually reduced in 0.5 V steps 5.0 V to examine the changes to the response by the cooling effect on the sensor as the voltage decreased. The hydrogen sulfide gas showed the highest sensitivity compared to odorless air under approximately 2.5 V and the ammonia and toluene gases showed the highest sensitivity under approximately 5.0 V. In other words, the hydrogen sulfide gas reacted better in the low temperature range of the MOS sensor, and the ammonia and toluene gases reacted better in the high-temperature range. In order to analyze the response characteristics of the MOS sensor by temperature in a pattern, a two-dimensional (2D) x-y pattern analysis was introduced to clearly classify the hydrogen sulfide, ammonia, and toluene gases. The hydrogen sulfide gas was identified by a straight line with a slope of 1.73, whereas the ammonia gas had a slope of 0.05 and the toluene gas had a slope of 0.52. Therefore, the 2D x-y pattern analysis is suggested as a new way to classify these odorous substances.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.694-698
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• 2008

In hydrology, it is a difficult task to deal with multivariate time series such as modeling streamflows of an entire complex river system. Normal distribution based model such as MARMA (Multivariate Autorgressive Moving average) has been a major approach for modeling the multivariate time series. There are some limitations for the normal based models. One of them might be the unfavorable data-transformation forcing that the data follow the normal distribution. Furthermore, the high dimension multivariate model requires the very large parameter matrix. As an alternative, one might be decomposing the multivariate data into independent components and modeling it individually. In 1985, Lins used Principal Component Analysis (PCA). The five scores, the decomposed data from the original data, were taken and were formulated individually. The one of the five scores were modeled with AR-2 while the others are modeled with AR-1 model. From the time series analysis using the scores of the five components, he noted "principal component time series might provide a relatively simple and meaningful alternative to conventional large MARMA models". This study is inspired from the researcher's quote to develop a multivariate simulation model. The multivariate simulation model is suggested here using Principal Component Analysis (PCA) and Independent Component Analysis (ICA). Three modeling step is applied for simulation. (1) PCA is used to decompose the correlated multivariate data into the uncorrelated data while ICA decomposes the data into independent components. Here, the autocorrelation structure of the decomposed data is still dominant, which is inherited from the data of the original domain. (2) Each component is resampled by block bootstrapping or K-nearest neighbor. (3) The resampled components bring back to original domain. From using the suggested approach one might expect that a) the simulated data are different with the historical data, b) no data transformation is required (in case of ICA), c) a complex system can be decomposed into independent component and modeled individually. The model with PCA and ICA are compared with the various statistics such as the basic statistics (mean, standard deviation, skewness, autocorrelation), and reservoir-related statistics, kernel density estimate.

• The KIPS Transactions:PartD
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• v.10D no.2
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• pp.277-282
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• 2003

The knowledge discovery from web has been studied in many researches. There are some difficulties using web log for training data on efficient information predictive models. In this paper, we studied on the method to eliminate sparseness from web log data and to perform web user clustering. Using missing value imputation by Bayesian inference of MCMC, the sparseness of web data is removed. And web user clustering is performed using self organizing maps based on 3-D plot by principal component. Finally, using KDD Cup data, our experimental results were shown the problem solving process and the performance evaluation.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2227-2230
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• 2015

Background: Prostate cancer (PCa) is one of the most commonly diagnosed neoplasms and the second leading cause of cancer death in men in the Western world. Vitamin D (1,25dihydroxy vitamin D) is linked to many biological processes that influence oncogenesis but data on relations between its genetic variants and cancer risk have been inconsistent. The aim of this study was to determine associations between a vitamin D genetic polymorphism and 25-hydroxyvitamin D [25(OH)D] levels and prostate cancer. Materials and Methods: Genomic DNA was extracted from 124 Jordanian prostate cancer patients and 100 healthy volunteers. Ethical approval was granted from the ethical committee at Hashemite University and written consent was given by all patients. PCR was used to amplify the vitamin D receptor Fok1 polymorphism fragment. 25(OH)D serum levels were measured by competitive immunoassay. Results: All genotypes were in Hardy-Weinberg equilibrium. Genotype frequency for Fok1 genotypes FF, Ff and ff was 30.7%, 61.3% and 8.06%, for prostate cancer patients, while frequencies for the control group was 28.0%, 66.0% and 6.0%, respectively, with no significant differences. Vitamin D serum level was significantly lower in prostate cancer patients (mean 7.7 ng/ml) compared to the control group (21.8 ng/ml). No significant association was noted between 25(OH)D and VDR Fok1 gene polymorphism among Jordanians overall, but significant associations were evident among prostate cancer patients (FF, Ff and ff : 25(OH)D levels of 6.2, 8.2 and 9.9) and controls (19.0, 22.5 and 26.3, respectively). An inverse association was noted between 25(OH)D serum level less than 10ng/ml and prostate cancer risk (OR 35.5 and 95% CI 14.3- 88.0). Conclusions: There is strong inverse association between 25(OH)D serum level less than 10ng/ml level and prostate cancer risk.

• Biomolecules & Therapeutics
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• v.3 no.2
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• pp.97-103
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• 1995

The purpose of this study was to determine pharmacokinetic parameters of BR-28702-2, a new antineoplastic agent which is the conjugate of nucleotide and phospholipid, and to compare them with those of ara-C. Male rats were cannulated in the left femoral vein and received a single i.v. bolus dose of either BR-28702-2 or ara-C. BR-28702-2 was also administered i.p. and plasma samples were analyzed by reversedphase HPLC. The t$_{1}$2($\beta$)/ of ara-C(1.22 hr.) was significantly smaller than that of BR-28702-2(4.420 hr.). The absolute bioavailability of BR-28702-2 after i.p. injection was 1.125%. This lower bioavailability, together with previous reports that marked antineoplastic activity was observed when given i.p., indicates that BR-28702-2 would act as a depot system to release active moieties. Further works, therefore, need to be done to characterize active metabolites.

• Journal of Biomedical Engineering Research
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• v.31 no.6
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• pp.456-463
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• 2010

In the present study, we proposed a new subspace scanning algorithm to enhance the spatial resolution of electroencephalography (EEG) and magnetoencephalography(MEG) source localization. Subspace scanning algorithms, represented by the multiple signal classification (MUSIC) algorithm and the first principal vector (FINE) algorithm, have been widely used to localize asynchronous multiple dipolar sources in human cerebral cortex. The conventional MUSIC algorithm used principal component analysis (PCA) to extract the noise vector subspace, thereby having difficulty in discriminating two or more closely-spaced cortical sources. The FINE algorithm addressed the problem by using only a part of the noise vector subspace, but there was no golden rule to determine the number of noise vectors. In the present work, we estimated a non-orthogonal signal vector set using independent component analysis (ICA) instead of using PCA and performed the source scanning process in the signal vector subspace, not in the noise vector subspace. Realistic 2D and 3D computer simulations, which compared the spatial resolutions of various algorithms under different noise levels, showed that the proposed ICA-MUSIC algorithm has the highest spatial resolution, suggesting that it can be a useful tool for practical EEG/MEG source localization.

• Korean Management Science Review
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• v.20 no.2
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• pp.113-133
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• 2003

This study developed the ISM (Electronic Store Success Model) by basing upon the revised D&M IS Success Model and reflecting the characteristics of marketing and e business. The theoretical rationale of this model was as following : 1) Though the revised D&M IS Success Model (2002) must be more logical and complete model than the original D&M IS Success Model (1992), it did not reflect characteristics of marketing and e business. 2) In the marketing studios, Service Quality has been suggested as one of basic strategies for success. 3) In e business studies, Trust has been emerging as a potentially important antecedent of e loyalty. 4) There has been a paradigm shift from satisfaction to loyalty in marketing emphasis. 5) Nowadays, ERP (Enterprise Resource Planning) has been pervaded in many organizations and has supported PCA (Profit Center Accounting) or Channel based Accounting, so it has not been difficult to evaluate financial performance of Electronic Store. The ESM that has six dimensions (System Quality, information Quality. Service Quality, Trust, Loyalty, Financial Performance) and expresses the causal relationship among them was proposed and was compared with BSC (Balanced Scorecard), WebQual, and EWAM (Extended Web Assessment Method). The results showed that the ESM coincides with BSC and contains dimensions of WebQual, and EWAM.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.199-199
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• 1994

Thioglycerol과 glycerol로부터 rac-1-S-octa-decyl-2-O-palmitoyl-1-S-thioglycerol-3-phosphate (DL -PTBA-P)와 rac-1-O-octadecyl-2-O-palmitoyl-g1ycerol-3-phosphate (DL-PBA-P)등을 합성하였고, 이들에 ara-C 유도체인 ara-CMP morpholidate를 반응시켜 최종 산물인 ara-CDP-DL-PCA, ara-CDP-DL-PBA, ara-CDP-DL-PTCA 및 ara-CDP-DL-PTBA등을 합성하였다. 이들 최종산믈의 항암효과는 L1210 lymphoid leukemia, colon 26 carcioma, M5076 sarcoma, C-1300 neuroblastoma, 3-Lewis lung carcinoma, WEHI-3B leukemia, human colon cancer, hum an pancreatic cancer 등의 암세포주를 사용하여 실험하였다. L1210를 DB/2J의 뇌막 또는 복강, DBA/1J의 복강내에 이식하여 ara-C, Ehss thioether lipid의 ara-C 유도체 (ara-CDP-L-DP, ara-CDP-DL-PCA, ara-CDP-DL-PBA, ara -CDP-DL-PTCA, ara-CDP-D-PTBA, ara-CDP-L-PTBA, ara-CDP-DL-PTBA)를 단일 투여 또는 중복 투여하였고, 3-Lewis는 C57BL/6 의 발바닥 피하, colon26은 BALB/C의 견갑상부 히아조직, M5076은 C57BL/6의 피하, WEHI-3B는 BALB/C의 복강, C-1300는 A/strong Ros에 각각 이식한 후 ara-C 또는 ara-CDP-DL-PTBA를 단일 또는 중복 투여하였다.

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.84-93
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• 1993

It has been reported that ginseng is effective in the central nervous system, immune system, and the strong inflammatory responses. However, there has been no research report yet about the effect of ginseng on allergic hypersensitivity reactivity. To confirm the ginseng effects on the release of mediators(histamine. leukotrienes etc.) which cause the hypersensitivity reactivity and inflammatory response, we used actively sensitized guinea pig airway tissues by utilizing the superfusion technique. In this procedure. the contractile response and mediators released after antigen stimulation of sensitized tissues, and IgG and IgE antibody products were measured in sera of immunized animals. Then the results of the controll group were compared to those of ginseng pretreatment groups. In the total saponin(TS) and panaxatriol(PT) pretreatment, histamine release decreased by $20\%$ in the tracheal tissues after active sensitization by ovalbumin(OVA, 10mg/kg), but in the lung parenchyma, histamine release decreased by $40\%.$ Panaxadiol(PD) significantly decreased histamine release by $40\%$ in the both tissues after active sensitization. TS, PT and PD of ginseng poorly blocked leukotrienes (LTs) and prostagrandin $D_2(PGD_2)$ release(less than $10\%$). Ginseng TS and PT had no effect on the serum IgG antibody production by ovalbumin, whereas PD significantly increased serum IgG antibody contents(approximately by 2 times). However, $IgG_1$ antibody products in the serum of guinea pig actively sensitized with ovalbumin after PD pretreatment were decreased, compared to that with ovalbumin alone. IgE antibody production by passive cutaneous anaphylaxis(PCA) titer in the TS pretreatment increased 3 times more than in the absence of TS(PCA titer by PT was not detected). These studies show that some ginseng saponins can in part act to inhibit mediator release in antigen - induced airway smooth muscle by inducing the IgG antibody production which has been changed in the specificity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10C
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• pp.1007-1016
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• 2005

This paper presents a feature extraction method for shape based retrieval of 3D models. Since the feature descriptor of 3D model should be invariant to translation, rotation and scaling, it is necessary to preprocess the 3D models to represent them in a canonical coordinate system. We use the PCA(Principal Component Analysis) method to preprocess the 3D models. Also, we apply that to make a MBR(Minimum Boundary Rectangle) and a circumsphere. The proposed algorithm is as follows. We generate a circumsphere around 3D models, where radius equals 1(r=1) and locate each model in the center of the circumsphere. We produce the concentric spheres with a different radius($r_i=i/n,\;i=1,2,{\ldots},n$). After looking for meshes intersected with the concentric spheres, we compute the curvature of the meshes. We use these curvatures as the model descriptor. Experimental results numerically show the performance improvement of proposed algorithm from min. 0.1 to max. 0.6 in comparison with conventional methods by ANMRR, although our method uses .relatively small bins. This paper uses $R{^*}-tree$ as the indexing.