• Korean Chemical Engineering Research
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• 제58권2호
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• pp.224-229
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• 2020

머신러닝 기법을 활용하여 LDPE (Low Density Polyethylene) 공정의 이상을 사전 감지하고, 설비의 수명을 예측할 수 있는 기술을 소개한다. 안전성과 생산성 극대화를 위해, 화학 공정의 예상치 못한 이상을 사전에 감지하고 예방하는 것은 매우 중요하다. LDPE 공정은 3,000 kg/㎠g 이상까지 승압되는 고압 공정이기 때문에, ESD (Emergency Shutdown)가 발생하면 예상치 못한 부동이 발생하고, 그에 따른 보수 기간 증가로 인한 생산성 손실이 발생한다. 고압 공정의 주요 변수들의 운전 데이터를 수집하고, 비지도학습 머신러닝 기술을 활용하여, ESD의 사전 감지 모형을 개발하였다. 4회의 ESD를 2.4일 전에 감지하는 결과를 얻을 수 있었다. 더불어, 물리적으로 의미 있는 핵심 변수들을 활용하면, 고압 설비의 수명을 예측할 수 있음을 확인할 수 있었다.

• 정보과학회 논문지
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• 제44권7호
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• pp.668-673
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• 2017

최근 몇 년간 딥러닝(deep learning)은 음성 인식, 영상 인식, 물체 검출을 비롯한 다양한 패턴인식 분야에서 혁신적인 성능 발전을 거듭해왔다. 그에 비해 네트워크가 어떻게 작동하는지에 대한 깊은 이해는 잘 이루어지지 않고 있다. 본 논문은 효과적인 신경망 네트워크를 구성하기 위해 네트워크 파라미터들이 신경망 내부에서 어떻게 작동하고, 어떤 역할을 하고 있는지 분석하였다. Faster R-CNN 네트워크를 기반으로 하여 신경망의 과적합(overfitting)을 막는 드랍아웃(dropout) 확률과 앵커 박스 크기, 그리고 활성 함수를 변화시켜 학습한 후 그 결과를 분석하였다. 또한 드랍아웃과 배치 정규화(batch normalization) 방식을 비교해보았다. 드랍아웃 확률은 0.3일 때 가장 좋은 성능을 보였으며 앵커 박스의 크기는 최종 물체 검출 성능과 큰 관련이 없다는 것을 알 수 있었다. 드랍아웃과 배치 정규화 방식은 서로를 완전히 대체할 수는 없는 것을 확인할 수 있었다. 활성화 함수는 음수 도메인의 기울기가 0.02인 leaky ReLU가 비교적 좋은 성능을 보였다.

• Journal of Microbiology and Biotechnology
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• 제19권1호
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• pp.108-112
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• 2009

A simplified method for the purification of cholera toxin was developed. The 569B strain of Vibrio cholerae, a recognized hyper-producer of cholera toxin, was propagated in a bioreactor under conditions that promote the production of the toxin. The toxin was separated from the bacterial cells using 0.2-${\mu}m$ crossflow microfiltration, the clarified toxin was passed through the membrane into the permeate, and the bacterial cells were retained in the retentate. The 0.2-${\mu}m$ permeate was then concentrated 3-fold and diafiltered against 10 mM phosphate buffer, pH 7.6, using 30-kDa crossflow ultrafiltration. The concentrated toxin was loaded onto a cation exchange column, the toxin was bound to the column, and most of the impurities were passed unimpeded through the column. The toxin was eluted with a salt gradient of phosphate buffer, pH 7.0, containing 1.0 M NaCl. The peak containing the toxin was assayed for cholera toxin and protein and the purity was determined to be 92%. The toxin peak had a low endotoxin level of $3.1\;EU/{\mu}g$ of toxin. The purified toxin was used to prepare antiserum against whole toxin, which was used in a $G_{M1}$ ganglioside-binding ELISA to determine residual levels of toxin in an oral inactivated whole-cell cholera vaccine. The $G_{M1}$ ganglioside-binding ELISA was shown to be very sensitive and capable of detecting as little as 1 ng/ml of cholera toxin.

• 한국자동차공학회논문집
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• 제18권2호
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• pp.83-90
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• 2010

The windshield wiper consists of 4 parts: a blade, an arm, a linkage and a motor. The wiper blade makes contact with the windshield and is designed to be operated normally at an angle of 30~50 degrees to the front glass. If the contact pressure between the wiper blade and windshield surface is too high, noise and wear of the rubber will result. On the other hand, if the contact pressure is too low, the performance will do badly, since foreign substances such as dust and stains will not be removed well. The pressure and friction of the wiper blade has a great influence on its effectiveness in cleaning the front window. This is due to the contact of the rubber with the window. This paper presents the dynamic analysis method to estimate the performance of the flat type blade of the wiper system. The blade has a nonlinear characteristic since the rubber is an incompressible hyper-elastic and visco-elastic material. Thus, Structural dynamic analysis using a complex contact model for the blade is performed to find the characteristics of the blade. The flexible multi-body dynamic model is verified by the comparison between test and analysis result. Also, the optimization using the central composite design table is performed.

• Archives of Plastic Surgery
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• 제40권5호
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• pp.603-609
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• 2013

Background Although the conventional direct brow lift operation provides a simple means of managing lateral brow ptosis, the scars produced have been unacceptable. However, using the modifications proposed here, scarring showed remarkable improvement. This article reviews our experiences with the presented technique, mainly with respect to postoperative scarring. Methods Measured amounts of supra-eyebrow skin and subcutaneous fat were excised en bloc in the conventional manner under 'hyper-hydrated' local infiltration anesthesia. The lower flap and the edge of the upper flap were undermined above the muscular plane, and the orbicularis oculi muscle was directly suture-plicated and suspended upward to the distal frontalis muscle. Skin closure was performed in a basic plastic surgical manner. Results From April 2007 to April 2012, a consecutive series of 60 patients underwent surgery using the above method. The average width of the excised skin was 8 mm (range, 5-15 mm) at the apex of the eyebrow. Preoperative complaints were resolved without occurrence of significant complications. The surgical scars showed remarkable improvement and were negligible in the majority of the cases. Conclusions The direct brow lift operation combined with plication/suspension of the superior and lateral portion of the orbicularis oculi muscle provides a simple, safe, and predictable means of correcting lateral brow ptosis. The scars were acceptable to all of the patients. For proper management of the frontalis tone, upper blepharoplasty and/or repair of eyelid levator function must be considered in addition to brow lift procedures.

• 한국물환경학회지
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• 제36권1호
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• pp.48-54
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• 2020

This paper presents a screening protocol for the selection of solvents available for the solvent extraction desalination process. The desalination solvents hypothetically and theoretically require the capability of (1) Forming hydrogen bonds with water, (2) Absorbing some water molecules into its non-polar solvent layer, (3) Changing solubility for water-solvent separation, and (4) Rejecting salt ions during absorption. Similar to carboxylic acids, amine solvents are solvent chemicals applicable for desalination. The key parameter for selecting the potential solvent was the octanol-water partitioning coefficient (Kow) of which preferable value for desalination was in the range of 1-3. Six of the 30 amine solvents can absorb water and have a variable, i.e., temperature swing solubility with water molecule for water-solvent separation. Also, the hydrogen bonding interaction between solvent and water must be stronger than the ion-dipole interaction between water and salt, which means that the salt ions must be broken from the water and only water molecules absorbed for the desalination. In the final step, three solvents were selected as desalination solvents to remove salt ions and recover water. The water recovery of these three solvents were 15.4 %, 2.8 %, 10.5 %, and salt rejection were 76 %, 98 %, 95 %, respectively. This study suggests a new screening protocol comprising the theoretical and experimental approaches for the selection of solvents for the desalination method which is a new and challenges the desalination process in the future.

• 한국콘텐츠학회논문지
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• 제10권12호
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• pp.84-90
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• 2010

Viola와 Jones가 사용한 Haar-like 특징 기반 약분류기의 분별력을 개선하기 위하여, 2차 판별식에 기반한 판정 경계(decision boundary) 결정 방법을 제안한다. Viola와 Jones가 부스팅된 약분류기 앙상블을 사용해서 강분류기를 만들 때 사용한 단일 판정 경계 기반 약분류기는 특징 공간을 지나치게 단순하게 해석한 산물이어서 대부분의 경우 최적이 아니며, 객체 클래스와 배경 클래스 간을 효율적으로 분별하기에 흔히 너무 약하다. 이 논문에서 제안하는 2차 판별식 분석에 기반한 방법은 객체 클래스와 배경 클래스 사이에 다중 판정 경계를 사용하는 약분류기를 만들어준다. 1000개의 positive 샘플과 3000개의 negative 샘플을 훈련에 사용하고, 500개의 positive와 500개의 negative를 테스트에 사용한 차량 검출 실험을 통해서, 기존의 단일 문턱치 기반 약분류기 방식에 비해, 제안 기법이 더 적은 수의 분류기를 사용하면서도 더 우수한 분류 성능을 제공하는 것을 확인하였다.

• 복식문화연구
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• 제13권4호
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• pp.550-563
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• 2005

These days, photoshop and illustrator program can make a fashion illustration express easily and speedily, And they can also express a feeling and sensitivity of fashion illustrator by a tool and effect more than a manual work's media. The purpose of this study was to analyze a visual expression and characteristics in fashion illustration using 2D graphics. The method of this study was to analyze the fashion illustration books using 2D graphics. The visual expressions in fashion illustration using 2D graphics were as follows: Fashion illustration was based on a sketch or photography, and used a composition, drawing, mapping, painting, and manual work's re-touching. Characteristics of visual expression were as follows: First, a image composition was showed discontinuity and heterogeneity of image, new context and composition, and allowance of reality. Second, image transform was showed image overlap, body transformation by image recomposition, and deformed transformation by vector drawing. Third, hyper-real was showed precise touching, mechanical and neutral image, omission of background and focus of an object's characteristic and information. Fourth, following a realistic expression was showed simplified color, shading, dominant view point of fashion illustrator by omission, and daily lift style. Fifth, following a pictorial expression was showed non-fixed and irregular line, natural painting, and drawing and painting by conventional pictorial media. In conclusion, a photoshop and illustrator in 2D graphics will serve as a new media far fashion illustration with a manual work. And they will not only intensify a capacity as a commercial role of fashion illustration but also present a positive motive for students learning a fashion illustration.

• 복식문화연구
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• 제16권2호
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• pp.382-396
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• 2008

The purpose of this study is to analyze the transition of glamour style expressed in modern fashion throughout the history. The glamour style in modern fashion was categorized into five periods which are Hollywood glamour(H), Feminine glamour(F), Rich glamour(R), Decadent glamour(D), and Trash glamour(T). These categories were analyzed and compared in the viewpoint of aesthetic values deduced on the previous study. As a method of analysis, literature study and case study through the publications in aesthetics, history and preceding theses were used. The results of analysis are: Ostentatious luxury was suggested by extravagance of the movie star in H, the splendid American lifestyle in F, conspicuous consumption in R, fin de siecle bad taste in D and self-assured exposure in T. Mysterious idolatry was studied as exaggerated goddesshood of the movie star in H. It was expanded to celebrities including fashion models, television actresses, pop singers and young couture designers in the other periods. Artificial sensuality was originated from the femme fatale image of the courtesan as well as the traditional femininity of Victorian era in H. It was developed through exaggerated hourglass silhouette of the wife dressing in F. But an aggressiveness in R, a hyper-sexual femme fatale in D, an independent and defiant image of the showgirl in T were observed. Playful queerness stood out clearly by the fin de siecle phenomena. Though it was embodied in sexual perversive subculture, it emerged as hi fashion by young designers in the late R and became a crucial aesthetic value throughout D and T. It is more connected with the origins of glamour which arouses sexual ambiguity, crudity, aggressiveness and death. The continuity and discontinuity of the glamour style based on the theory of 'linked solution' were also analyzed.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
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• pp.84-86
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• 2008

회사들이 정보를 효율적으로 이용할 수 있도록 제어하고 필터링하는 일을 도와주는 고객 관계 마케팅이 등장하였으며, 더 나아가 고객이 원하는 제품을 예측하고 추천해 주기 위해 데이터 마이닝을 적용하고 있다. 본 논문에서는 데이터 마이닝의 연관 규칙을 이용한 적응적 고객 관계 관리 전략을 제안하였다. 제안된 방법으로는 연관 규칙을 이용하여 후보 고객 집합으로 빈발 고객을 구성하고 연관 고객들의 규칙을 생성한다. 생성된 연관 규칙의 향상도에 따라서 하이퍼 그래프 분할을 이용하여 구매 고객들의 효율적인 특성을 분석한다. 따라서 고객들에 대한 교차 판매와 격상 판매의 전략들을 도출하게 된다.