종합방법에 따른 고분자입자의 물설변화

황민진 ( Min Jin Hwang ),문희 ( Hee Moon ) 조선대학교 공학기술연구원 2008 공학기술논문지 Vol.1 No.2

The preparation of monodispers polymer particles has attracted considerable academic industrial due to their wide variety of applications. Size control and narrow size distribution are of fundamental importance for most application of polymer particles. In this study, sub-micron sized monodisperse polystyrene beads were prepared by various heterogeneous polymerization procedures including emulsion, soap-free emulsion and dispersion polymerization. The effects of different polymerization methodologies and reaction temperature on physical properties of polymer particles were studied. The particle size and the particle size distribution were examined by using particle size analyzer(PSA). The structure of polymer particle was investigated using scanning electron microscope(SEM).

커피박으로부터 만들어진 활성탄의 특성과 Acid orange 7 제거능

황민진(Min-Jin Hwang),고성철(Sung-Cheol Koh),장재수(Chang, Jae-Soo) 한국생태환경건축학회 2016 한국생태환경건축학회 학술발표대회 논문집 Vol.16 No.1

금속담지 활성탄의 인산염 흡착특성

황민진(Min Jin Hwang),황유식(Yu Sik Hwang),이원태(Wontae Lee) 大韓環境工學會 2015 대한환경공학회지 Vol.37 No.11

수계에 존재하는 인산염의 흡착제거 용량을 향상시키기 위하여, 참나무 기반 활성탄을 제조하였으며, 이때 Fe³⁺와 Al³⁺이온의 혼합물을 흡착제 표면에 담지 하였다. 금속담지 활성탄의 인산염의 흡착용량은 금속이온으로 표면을 개질 하지않은 활성탄에 비해 약 8배 높게 나타났다. 흡착평형량은 흡착반응의 온도가 증가할수록 증가하였으며, Langmuir 흡착등온식의 경향과 일치하였다. 제조된 금속담지 활성탄의 인산염 흡착제거공정은 흡열의 자발반응으로 진행되었음을 확인하였다. 흡착공정의 거동과 제거속도를 평가하기 위하여, 세공확산모델을 통해 내부 확산계수를 산출하였으며, 이는 실험결과와 매우 일치하였다. Oak wood based activated carbon was modified with surface impregnation of Fe³⁺ and Al³⁺ metal ions mixture for enhancements of phosphate adsorption capacity in aqueous solution. The phosphate adsorption capacity of the prepared metal impregnated carbon (MC) was about 8 times higher than that of the original activated carbon (OC). Adsorption equilibrium capacities of the phosphate increased with increasing system temperature. The adsorption equilibrium isotherm of phosphate on the prepared MC could be represented by the Langmuir equation. Thermodynamic parameters also indicated that adsorption system was spontaneous and endothermic reaction. The internal diffusion coefficient was measured to analyze the adsorption behavior and kinetic rate. To determine the internal diffusion coefficient, pore diffusion model (PDM) was employed and the result was in good agreement with experimental data.

PLS 및 복합 나노구체를 이용한 HEPA 필터 시험

황민진 ( Min Jin Hwang ),성동찬 ( Dong Chan Sung ),문희 ( Hee Moon ) 한국공업화학회 2013 공업화학 Vol.24 No.4

Monodispersed polystyrene latex spheres (PLS) and PS-MPS/silica composite nanospheres were used to test high efficiency particulate air (HEPA) filters. Prior to filter tests, all nanospheres used in this work were characterized by measuring their average particle diameters and coefficients of variation (CV) for assessing them as artificial dusts. The average particle sizes of PLS and composite nanospheres could be well controlled in the range of 100∼300 nm well by changing reaction temperature and the amount of a stabilizer during emulsion polymerization. The CV of all nanospheres were also in the range of 3∼7%, lower than 15% that is the criterion for monodispersed particle distributions. Furthermore the results of HEPA filter tests show that all nanospheres used were quite proper as artificial dusts for testing air filters.

CNN 보조 손실을 이용한 차원 기반 감성 분석

전민진(Min Jin Jeon),황지원(Ji Won Hwang),김종우(Jong Woo Kim) 한국지능정보시스템학회 2021 지능정보연구 Vol.27 No.4

Aspect Based Sentiment Analysis (ABSA), which analyzes sentiment based on aspects that appear in the text, is drawing attention because it can be used in various business industries. ABSA is a study that analyzes sentiment by aspects for multiple aspects that a text has. It is being studied in various forms depending on the purpose, such as analyzing all targets or just aspects and sentiments. Here, the aspect refers to the property of a target, and the target refers to the text that causes the sentiment. For example, for restaurant reviews, you could set the aspect into food taste, food price, quality of service, mood of the restaurant, etc. Also, if there is a review that says, The pasta was delicious, but the salad was not, the words steak and salad, which are directly mentioned in the sentence, become the “target.” So far, in ABSA, most studies have analyzed sentiment only based on aspects or targets. However, even with the same aspects or targets, sentiment analysis may be inaccurate. Instances would be when aspects or sentiment are divided or when sentiment exists without a target. For example, sentences like, Pizza and the salad were good, but the steak was disappointing. Although the aspect of this sentence is limited to “food,” conflicting sentiments coexist. In addition, in the case of sentences such as Shrimp was delicious, but the price was extravagant, although the target here is “shrimp,” there are opposite sentiments coexisting that are dependent on the aspect. Finally, in sentences like The food arrived too late and is cold now. there is no target (NULL), but it transmits a negative sentiment toward the aspect service. Like this, failure to consider both aspects and targets – when sentiment or aspect is divided or when sentiment exists without a target – creates a dual dependency problem. To address this problem, this research analyzes sentiment by considering both aspects and targets (Target-Aspect-Sentiment Detection, hereby TASD). This study detected the limitations of existing research in the field of TASD: local contexts are not fully captured, and the number of epochs and batch size dramatically lowers the F1-score. The current model excels in spotting overall context and relations between each word. However, it struggles with phrases in the local context and is relatively slow when learning. Therefore, this study tries to improve the models performance. To achieve the objective of this research, we additionally used auxiliary loss in aspect-sentiment classification by constructing CNN(Convolutional Neural Network) layers parallel to existing models. If existing models have analyzed aspect-sentiment through BERT encoding, Pooler, and Linear layers, this research added CNN layer-adaptive average pooling to existing models, and learning was progressed by adding additional loss values for aspect-sentiment to existing loss. In other words, when learning, the auxiliary loss, computed through CNN layers, allowed the local context to be captured more fitted. After learning, the model is designed to do aspect-sentiment analysis through the existing method. To evaluate the performance of this model, two datasets, SemEval-2015 task 12 and SemEval-2016 task 5, were used and the f1-score increased compared to the existing models. When the batch was 8 and epoch was 5, the difference was largest between the F1-score of existing models and this study with 29 and 45, respectively. Even when batch and epoch were adjusted, the F1-scores were higher than the existing models. It can be said that even when the batch and epoch numbers were small, they can be learned effectively compared to the existing models. Therefore, it can be useful in situations where resources are limited. Through this study, aspect-based sentiments can be more accurately analyzed. Through various uses in business, such as development or establishing marketing strategies, both consumers and sellers will be able to

나프록센이 각인된 생분해성 고분자 기반 다층 바이오소재의 제조 및 약물 방출 특성

조은비,김한성,황민진,윤순도,Eun-Bi Cho,Han-Seong Kim,Min‑Jin Hwang,Soon-Do Yoon 한국공업화학회 2023 공업화학 Vol.34 No.2

본 연구는 allbanggae starch (ABS), polyvinyl alcohol (PVA), alginic acid (SA)를 이용하여 naproxen (NP) 각인 starch 기반 다층 바이오소재를 제조하고, 물리화학적 특성과 약물 방출 제어 효과를 조사하였다. 또한, FE-SEM과 FT-IR 분석에 의해 제조한 다층 바이오소재의 특성을 조사하였다. 약물 방출 제어 효과와 경피 약물 전달 시스템의 적용 가능성을 확인하기 위해 NP 각인 다층 바이오소재로부터 NP 방출 특성을 사람의 체온인 36.5 ℃에서 다양한 pH buffer solution과 인공 피부를 이용하여 확인하였다. NP는 낮은 pH보다 높은 pH에서 1.3배 더 빠른 방출을 나타냈고, single-layer 바이오소재에서보다 multi-layer 바이오소재에서 약 4.0배 느린 방출이 일어남을 확인하였다. 인공 피부 방출에서도 동일하게 single-layer 바이오소재보다 multi-layer 바이오소재에서 약 4.0배 더 느린 약물 방출 결과를 나타내었다. 또한, double-layer와 triple-layer 바이오소재 모두 12시간 동안 지속적으로 NP가 방출되었음을 확인 하였다. NP 방출 mechanism을 규명하기 위해 수학적 모델링에 적용하여 비교했을 때, pH buffer solution에서의 방출은 Fickian diffusion mechanism, 인공 피부 방출은 empirical mechanism에 적합한 것을 확인하였다.

고분자 필름이 코팅된 QCM 시스템에 의한 방향족 화합물의 흡착

문희 ( Hee Moon ),황민진 ( Min Jin Hwang ),심왕근 ( Wang Geun Shim ) 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.2

A quartz crystal microbalance (QCM) system coated with poly (isobutylene), polystyrene, and poly (methyl methacrylate) has been prepared to measure the adsorption amounts of benzene, toluene, and p-xylene at very low pressures. The resonant frequency shift of the QCM system is proportional to the increase in pressure in all experiments. The Henry`s constants for all adsorbates on the polymer films are obtained from experimental data and compared with the minimum adsorption potential energies between adsorbates and the polymer films. In general, there is an explicit correlation between adsorption amount and the minimum adsorption potential energy

QCM기반 NO2와 SO2 감지용 센서시스템

문희 ( Hee Moon ),황민진 ( Min Jin Hwang ),심왕근 ( Wang Geun Shim ) 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.2

The effects of sensing materials, coating methods, diluent gases, and temperature have been studied in detail to make a quartz crystal microbalance based adsorption sensor system for detecting gases. In particular, sensor elements for detecting NO2 and SO2, that are known as major air pollutants, have been prepared by coating two different polymers, polypyrrole and poly(3,4-ethylenedioxythiophene). The sensor elements prepared in this work have high sensitivity and selectivity for NO2 and SO2 at ppm level concentrations. It was proven that the sensing characteristics and response rate of the sensing elements are highly dependent on the coating method and the loading mass of sensing materials.

폐플라스틱과 키토산을 활용한 입상형 활성탄의 염료 흡착특성 평가

김은식 ( Eun-sik Kim ),윤순도 ( Soon-do Yoon ),김지윤 ( Ji-yoon Kim ),황민진 ( Min-jin Hwang ) 한국키틴키토산학회 2020 한국키틴키토산학회지 Vol.25 No.4

염색 폐수 처리를 위한 흡착제를 개발하기 위하여, 폐 PET 수지로부터 활성탄을 개발하였으며, 이를 활용한 입상형 키토산 비드를 제조하였다. 활성제의 함량에 따른 활성탄의 세공특성과 methylene blue (MB) 흡착 제거효율을 평가하였다. MB 수용액에 대한 ACPRs의 최대흡착량은 ACPR-15에서 694.1 mg/g으로 나타났으며, Langmuir 흡착등온식으로 설명할 수 있었다. 폐 PET 수지를 활용한 활성탄의 흡착제거 공정 효율을 극대화하기 위해, 키토산을 활용하여 입상형 비드 CB-ACPR-15를 제조하였다. 흡착반응 온도 증가에 따라 염료의 제거 효율은 저하되었으며 Sips 흡착등온식과 Gibbs 자유에너지를 통해 설명하였다. 또한, MB 수용액의 초기농도에 따라 흡착속도가 증가되는 현상을 세공확산모델을 통해 분석하였다. The activated carbons (ACPRs) derived from Polyethylene terephthalate (PET) residues was prepared using wet impregnation of potassium hydroxide. The influence of the impregnation ratio on textural properties were evaluated. The overall porosity was improved with increasing impregnation ratio. For applying adsorption-based wastewater treatment system, the chitosan granules (CB-ACPR) combined with the ACPRs were prepared. In order to estimate the methylene blue (MB) adsorption capability of the CB-ACPR, the adsorption equilibrium isotherm and kinetic studies were evaluated. The adsorption equilibrium isotherm of MB on the CB-ACPR was represented by Sips isotherm model. The pore diffusion model was employed to determine the internal diffusion coefficient and the results was in good agreement with experimental kinetic data. Adsorption equilibrium capacities and diffusion coefficients of the MB increased with initial concentration.

해수 양식장의 질소제거를 위한 흡착공정 연계 생물반응조의 성능평가

하선경(Seongyeong Ha),김도영(Doyoung Kim),김채경(Chaekyeong Kim),황민진(Min-Jin Hwang) 대한환경공학회 2021 대한환경공학회 학술발표논문집 Vol.2021 No.11