• 한국정밀공학회지
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• 제14권12호
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• pp.24-29
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• 1997

Recently, Genetic Algorithm(GA), which is a stochastic direct search strategy that mimics the process of genetic evolution, is widely adapted into a search procedure for structural optimization. Contrast to traditional optimal design techniques which use design sensitivity analysis results, GA is very simple in their algorithms and there is no need of continuity of functions(or functionals) any more in GA. So, they can be easily applicable to wide area of design optimization problems. Also, owing to multi-point search procedure, they have higher porbability of convergence to global optimum compared to traditional techniques which take one-point search method. The methods consist of three genetics opera- tions named selection, crossover and mutation. In this study, a method of finding the omtimum size and topology of drilling machine is proposed by using the GA, For rapid converge to optimum, elitist survival model,roulette wheel selection with limited candidates, and multi-point shuffle cross-over method are adapted. And pseudo object function, which is the combined form of object function and penalty function, is used to include constraints into fitness function. GA shows good results of weight reducing effect and convergency in optimal design of drilling machine.

• 한국임상수의학회지
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• 제40권3호
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• pp.225-229
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• 2023

In three dogs showing cerebellar ataxia, the onset of clinical signs varied from a young age of five months to age 13 years. Qualitative magnetic resonance imaging (MRI) revealed various degrees of cerebellar atrophy, and a tentative diagnosis of cerebellar cortical degeneration was made. Quantitative analysis using the brainstem to the cerebellar cross-sectional area ratio (BS:CBM ratio) and T2-signal intensity histograms were obtained to perform an objective evaluation. These techniques have the advantage of being easy and fast to evaluate. These quantitative analyses revealed the severity of cerebellar cortical degeneration in the three dogs as mild, moderate, and severe. Dogs 2 and 3 were identified as abnormal on the relative cerebrospinal fluid (CSF) space using T2-signal intensity histograms but were normal on the BS:CBM ratio. This suggests that the T2-signal intensity histograms may have higher sensitivity than BS:CBM ratio.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.289-290
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• 2022

동맥경화증은 경동맥 혈관 벽이 두꺼워지는 질병으로 진단을 위해 혈관 벽의 두께를 모니터링하는 것이 중요하다. 본 연구에서는 경동맥 MRI 영상에서 324개의 라디오믹스 특징을 추출하고 머신러닝 기법을 이용하여 동맥경화증을 진단하는 모델을 제안한다. 라디오믹스 특징을 통해 로지스틱 회귀, 서포트 벡터 머신, 랜덤 포레스트, XGBoost의 총 4가지 분류 모델을 학습하였다. 5-fold 교차 검증에서 가장 높은 성능의 모델인 XGBoost는 정확도 0.9023, 민감도 0.9517, 특이도 0.8035, AUC 0.8776의 결과값을 보여준다.

• 한국축산식품학회지
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• 제43권6호
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• pp.989-1001
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• 2023

Processed foods containing pork fat tissue to improve flavor and gain economic benefit may cause severe issues for Muslims, Jews, and vegetarians. This study aimed to develop an indirect enzyme-linked immunosorbent assay (iELISA) based on a monoclonal antibody specific to thermal stable-soluble protein in pork fat tissue and apply it to detect pork fat tissue in heat-processed (autoclave, steam, roast, and fry) beef meatballs. To develop a sensitive iELISA, the optimal sample pre-cooking time, coating conditions, primary and secondary dilution time, and various buffer systems were tested. The change in the iELISA sensitivity with different 96-well microtiter microplates was confirmed. The detection limit of iELISA performed with an appropriate microplate was 0.015% (w/w) pork fat in raw and heat-treated beef. No cross-reactions to other meats or fats were shown. These results mean that the iELISA can be used as an analytical method to detect trace amounts of pork fat mixed in beef.

• Journal of Astronomy and Space Sciences
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• 제40권4호
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• pp.259-266
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• 2023

The Standard Model (SM) does not provide an information for 26% of dark matter of the universe. In the dark sector, dark matter is supposed to be linked with the hypothetical particles called dark photons that have similar role to photons in electromagnetic interaction in the SM. Besides astronomical observation, there are studies to find dark matter candidates using accelerators. In this paper, we searched for dark photons using future electron-positron colliders, including Circular Electron Positron Collider (CEPC)/CEPC, Future Circular Collider (FCC-ee)/Innovative Detector for Electron-positron Accelerator (IDEA), and International Linear Collider (ILC)/International Large Detector (ILD). Using the parameterized response of the detector simulation of Delphes, we studied the sensitivity of a double dark photon mode at each accelerator/detector. The signal mode is double dark photon decay channel, e⁺e^- → A'A', where A' (dark photon with spin 1) decaying into a muon pair. We used MadGraph5 to generate Monte Carlo (MC) events by means of a Simplified Model. We found the dark photon mass at which the cross-sections were the highest for each accelerator to obtain the maximum number of events. In this paper we show the expected number of dark photon signal events and the detector efficiency of each accelerator. The results of this study can facilitate in the dark photon search by future electron-positron accelerators.

• Applied Microscopy
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• 제50권
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• pp.25.1-25.11
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• 2020

Scanning acoustic microscopy (SAM) or Acoustic Micro Imaging (AMI) is a powerful, non-destructive technique that can detect hidden defects in elastic and biological samples as well as non-transparent hard materials. By monitoring the internal features of a sample in three-dimensional integration, this technique can efficiently find physical defects such as cracks, voids, and delamination with high sensitivity. In recent years, advanced techniques such as ultrasound impedance microscopy, ultrasound speed microscopy, and scanning acoustic gigahertz microscopy have been developed for applications in industries and in the medical field to provide additional information on the internal stress, viscoelastic, and anisotropic, or nonlinear properties. X-ray, magnetic resonance, and infrared techniques are the other competitive and widely used methods. However, they have their own advantages and limitations owing to their inherent properties such as different light sources and sensors. This paper provides an overview of the principle of SAM and presents a few results to demonstrate the applications of modern acoustic imaging technology. A variety of inspection modes, such as vertical, horizontal, and diagonal cross-sections have been presented by employing the focus pathway and image reconstruction algorithm. Images have been reconstructed from the reflected echoes resulting from the change in the acoustic impedance at the interface of the material layers or defects. The results described in this paper indicate that the novel acoustic technology can expand the scope of SAM as a versatile diagnostic tool requiring less time and having a high efficiency.

• Parasites, Hosts and Diseases
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• 제26권4호
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• pp.245-254
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• 1988

유구낭미충(이하 낭미충)(Cysticercus cellulosae)에서 추출한 조항원으로 낭미충증(cysticercosis), 스파르가눔중(sparganosis) 및 포충중(hydatidosis) 환자 및 정상인 혈청내 IgG 항체와의 혈청학적 반응을 ELISA 및 EITB 방법으로 추적하였다. ELISA에서 낭미충의 조항원 단백은 스파르가눔중 환자 혈청과의 교차 반응도 보였고, 포충증 환자 혈청에 대해서는 낭미충 환자 혈청보다 오히려 높은 흡광도(O.D.)를 보였다. 낭미충 조항원을 SDS-PAGE로 전기영동한 결과 260 KDa∼22 KDa 범위에서 31개의 polypeptide band를 얻었으며 이 중 11개의 분획이 강한 염색성을 나타내었다. 낭미충 조항원과 낭미충중 환자 혈청과의 EITB 반응에서 22개의 항원대가 관찰되었으며 이 중 104 KDa, 82 KDa, 78 KDa 및 59 KDa는 모든 검사 혈청에서 인지되었다. 또 22개의 항원대 중 12개는 정상인 혈청에서도 반응이 관찰되어 교차반응하는 비특이성 항원 성분으로 해석되었다. 낭미충 조항원과 스파르가눔증 환자 혈청과의 반응에서 11개의 항원대가 인지되었으며 이 중 낭미충증 환자 혈청과 교차반응하는 9개의 항원대가 인지되었다. 나머지 163 KDa 및 131 KDa 항원대는 스파르가눔 환자에서만 동정되었다. 낭미충 조항원과 포충증 환자 혈청과의 반응에서는 21개의 항원대가 인지되었는데, 이 중 63 KDa는 포충증 환자에서만 인지되었고 나머지는 낭미충증 환자 혈청과 교차반응하는 항원대이었다. 한편 낭미충 조항원 중 104 KDa, 82 KDa, 72 KDa, 59 KDa및 34 KDa는 낭미충증, 스파르가눔증 및 포충중 환자와 정상인의 혈청에서도 모두 교차반응을 일으키는 항원이었다.

• 한국식품과학회지
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• 제30권6호
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• pp.1273-1278
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• 1998

Biotin의 분석에 사용되는 기존의 미생물 분석법보다 신속하고 간편한 효소-단백질결합 분석법(enzyme protein binding assay; EPBA)을 개발하였다. Biotin-KLH conjugate와 streptavidin을 이용한 EPBA에서, biotin의 활성을 갖는 biocytin에 대하여 각각 109% $(IC_{50}=0.3\;ppb)$와 197% $(IC_{50}=0.8\;ppb)$의 교차반응을 보였으나 desthiobiotin과 diaminobiotin 그리고 2-iminobiotin에서는 교차반응을 보이지 않았다. Streptavidin과 biotin-KLH conjugate를 이용한 EPBA에서 검출범위는 각각 $0.01{\sim}30\;ng/mL$과 $0.01{\sim}1.0\;ng/mL(ppb)$로 나타났다. 우유시료와 과일 플레이크 그리고 당근-파인애플 쥬스에 대한 spike test에서 EPBA(biotin-KLH conjugate)와 미생물 분석법(microbiological assay; MBA)간의 상관관계는 r=0.994로 매우 높은 것으로 나타났다. 그러나 MBA는 biocytin과 desthiobiotin에 대하여 각각 80.1%, 66.7%의 교차반응을 나타냈다. 검출범위도 $0.1{\sim}0.5\;ng/mL(ppb)$로 분석 범위가 매우 제한되어 있었다. 그러므로 EPBA에 의하여 biotin을 분석하는 것이 기존의 미생물 분석법에 비하여 검출 감도나 검출 범위, 교차반응 그리고 분석시간 등의 여러 가지 면에서 우수한 것으로 확인되었다.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.645-654
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• 1995

Porphyromonas endodontalis is a black-pigmented anaerobic Gram negative rod which is associated with endodontal infections. It has been isolated from infected dental root canals and submucous abscesses of endodontal origin. DNA probe is an available alternative, offering the direct detection of a specific microorganism. Nucleic-acid probes can be off different types: whole different: whole-genomic, cloned or oligonucleotide probes. Wholegenomic probes are the most sensitive because the entire genome is used for possible hybridization sites. However, as genetically similar species of bacteria are likely to be present in specimences, cross-reactions need to be considered. Cloned probes are isolated sequences of DNA that do not show cross-reactivity and are produced in quantity by cloning in a plasmid vector. Cloned probes can approach the sensitivity found with whole-genomic probes while avoiding known cross-reacting species. Porphyromonas endodontalis ATCC 35406 (serotype $O_1K_1$) was selected in this experiment to develop specific cloned DNA probes. EcoR I-digested genomic DNA fragments of P. endodontalis ATCC 35406 were cloned into pUC18 plasmid vector. From the E. coli transformed with the recombinant plasmid 4 clones were selected to be tested as specific DNA probes. Restriction-digested whole-genomic DNAs prepared from P. gingivalis 38(serotype a), W50(serotype b), A7A1-28(serotype C), P. intermedia 9336(serotype b), G8-9K-3(serotype C), P. endodontalis ATCC 35406(serotype $O_1K_1$), A. a Y4(serotype b), 75(serotype a), 67(serotype c), were each seperated on agarose gel electrophoresis, blotted on nylon membranes, and were hybridized with digoxigenin-dUTP labeled probe. The results were as follows: 1. Three clones of 1.6kb(probe e), 1.6kb(probe f), and 0.9kb(probe h) in size, were obtained. These clones were identified to be a part of the genomic DNA of P. endodontalis ATCC 35406 judging from their specific hybridization to the genomic DNA fragments of their own size on Southern blot. 2. The clones of 4.9kb(probe i) was identified to be a part of the genomic DNA of P. endodontalis ATCC 35406. but not to specific for itself. It was hybridized to P. gingivalis A7A1-28, P. intermedia G89K-3.

• Investigative Magnetic Resonance Imaging
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• 제26권1호
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• pp.10-19
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• 2022

Purpose: To evaluate whether the added value of contrast leakage information from dynamic susceptibility contrast magnetic resonance imaging (DSC MRI) is a better prognostic imaging biomarker than the cerebral blood volume (CBV) value in distinguishing true progression from pseudoprogression in glioblastoma patients. Materials and Methods: Forty-nine glioblastoma patients who had undergone MRI after concurrent chemoradiotherapy with temozolomide were enrolled in this retrospective study. Twenty features were extracted from the normalized relative CBV (nCBV) and extraction fraction (EF) map of the contrast-enhancing region in each patient. After univariable analysis, we used multivariable stepwise logistic regression analysis to identify significant predictors for differentiating between pseudoprogression and true progression. Receiver operating characteristic (ROC) analysis was employed to determine the best cutoff values for the nCBV and EF features. Finally, leave-one-out cross-validation was used to validate the best predictor in differentiating between true progression and pseudoprogression. Results: Multivariable stepwise logistic regression analysis showed that MGMT (O⁶-methylguanine-DNA methyltransferase) and EF max were independent differentiating variables (P = 0.004 and P = 0.02, respectively). ROC analysis yielded the best cutoff value of 95.75 for the EF max value for differentiating the two groups (sensitivity, 61%; specificity, 84.6%; AUC, 0.681 ± 0.08; 95% CI, 0.524-0.837; P = 0.03). In the leave-one-out cross-validation of the EF max value, the cross-validated values for predicting true progression and pseudoprogression accuracies were 69.4% and 71.4%, respectively. Conclusion: We demonstrated that contrast leakage information parameter from DSC MRI showed significance in differentiating true progression from pseudoprogression in glioblastoma patients.