포항공대 분자 모델링 시스템 개발 및 생화학 분자 내에서의 Zn(II)의 배위에 관한 이론적 연구

윤장우 포항공과대학 1992 국내석사

포항공대 분자그래픽스 시스템 개발 및 물분자 집합체에 관한 이론적 연구

김성욱 포항공과대학 1990 국내석사

Automatic Attribute Extraction using Domain Expertise in Fashion and its Evaluation on Compatibility and Diagnosis

배승예 포항공과대학교 융합대학원 2022 국내석사

Predicting outfit compatibility refers to determining whether fashion items look good if worn together. In recent years, a few studies have used visual-semantic space in outfit compatibility prediction and proposed modeling or equations to capture high-level information. However, the proper textual attributes help to form a more accurate visual-semantic space, and providing the domain-specific details allows the compatibility model to learn semantically more robust information. This thesis proposes a method to extract the domain-specific fashion attributes using color expertise. The proposed method maps the pattern and adjectives corresponding to the closest one among Kobayashi’s color triplets of each item as fashion style concepts. Then, it adjusts the resulting concepts by zero-shot classification of fine-tuned CLIP to make them more distinguishable. Experiments with four datasets that differ in the composition of the extracted concepts in text attributes are conducted to validate the proposed method. The dataset, including adjusted fashion style concepts, outperforms the prior baseline with a 14% increase in FITB accuracy of outfit compatibility prediction. The result shows that high-level semantic features are prominent to get the unified representation through visual-semantic space and verifies that our approach is more applicable to the fashion domain for outfit diagnosis.

Molecular cloning and expression of preprocarboxypeptidase A from bovine pancreas

김국현 포항공과대학 1994 국내석사

LPG/LTR 및 Preview 제어를 이용한 능동 현가 제어기 설계

전진훈 포항공과대학교 1996 국내박사

Measuring Democratic Values Oriented by AI News Recommendation Algorithms

황수현 포항공과대학교 융합대학원 2023 국내석사

The market for news in Korea is increasingly using AI. The Korea Press Foundation estimated that 79.2% of Koreans would view news online portal sites in 2021, and Naver and Kakao had already transitioned from human to AI editing of news recommendations in 2017, accounting for more than 90% of the market share for portals. The truth, however, is that there is no established yardstick for judging AI news, and this is accompanied by a lack of awareness of AI’s market share in the news. The purpose of this study was to evaluate AI news recommendations in light of the democratic values that Korean society pursues. We propose three models of democracy, liberal, participatory, and deliberative, to achieve this purpose, in addition to evaluating how well Naver’s and Kakao’s AI-recommended news adhered to the principles of each democracy model, i.e., freedom, social involvement, and discussion. We identified that Kakao is closer to the deliberative democracy model, whereas Naver is closer to the liberal model, such that Naver’s news recommendation algorithm is better suited to guaranteeing people’s freedom of news selection. On the other side, we interpret that under Kakao’s algorithm, members are contributing substantially more to attaining agreement via debate. All democratic values are relative, and we cannot discern between excellent and terrible algorithms merely because they concentrate on a certain value. The key is to understand where algorithms fit into the map of values that each culture pursues, and this study is an effort to do just that. This is also crucial because it sets a precedent for the ultimate objective of putting in place an algorithm that complies with Korean society’s values. 한국 뉴스 시장에서 AI가 차지하는 비중은 갈수록 증가하고 있다. 한국언론진흥재단에 따르면 2021년 한국인의 79.2%는 뉴스를 볼 때 인터넷 포털 사이트를 이용하며, 포털 시장 점유율 90% 이상을 차지하는 네이버와 카카오는 2017년에 이미 뉴스 추천을 사람 편집에서 AI 편집으로 전환했다. 그러나 뉴스 시장에서 AI가 차지하는 비중에 대한 인식이 부족할뿐더러, AI 뉴스를 평가하는 합의된 기준 또한 부재한 것이 현실이다. 이 연구는 AI가 추천한 뉴스를 우리 사회가 추구하는 민주적 가치에 기준하여 평가하기 위한 것이다. 이를 위해 3가지 민주주의 모델 – 자유주의, 참여주의, 심의주의 – 을 상정하고, 네이버와 카카오의 AI 추천 뉴스가 각 민주주의 모델이 추구하는 가치 – 자유, 사회 참여, 토론 및 합의 – 와 얼마나 가까운지, 혹은 먼지를 측정하였다. 실험 결과 네이버는 자유주의 모델에, 카카오는 참여주의와 심의주의 모델에 더 가까운 것으로 나타났다. 이는 네이버 뉴스 추천 알고리즘은 개인이 뉴스를 선택할 자유를 보장하는 데 비교적 더 많이 기여하는 반면, 카카오 뉴스 추천 알고리즘은 구성원들이 사회의 다양한 사안에 참여하고, 토론하여 합의를 이루는 데 상대적으로 더 많이 기여하고 있다는 의미로 해석할 수 있다. 민주적 가치는 모두 상대적이며, 특정 가치에 집중한다는 이유로 좋은 알고리즘과 나쁜 알고리즘을 가를 수 없다. 중요한 것은 각 사회가 추구하는 가치의 지형도에 알고리즘이 어떻게 위치하고 있는지를 인지하는 것이며, 이 연구는 그 인지를 위한 작업이다. 이는 또한 한국 사회의 가치에 부합하는 알고리즘 구현이라는 최종 목표의 선행 작업이라는 데 의의가 있다.

Synthesis and application of petal-shaped bismuth subcarbonate (Bi2O2CO3) by the immersion method

홍대명 포항공과대학교 일반대학원 2021 국내석사

Bismuth catalyst is a good candidate for producing formate (formic acid) via electro-chemical reduction of CO2. Also, it has known that various bismuth oxide derivatives are used to improve catalytic performance such as Bi2O3, BiOX (X is Cl, Br, I) and Bi2O2CO3. Among them, Bi2O2CO3 has a crystal structure of (Bi2O2)2+ layers interleaved by slabs comprising CO32- groups, and has various two-dimensional structures such as nanosheets or nanoflowers. In general, many studies have been performed as photocatalys ts for removing environmental pollutants, and recently, catalyst studies for generating for-mate by electrochemically reducing CO2 have been conducted. Thus the research on Bi2O2CO3 catalyst has become attractive because of these excel-lent catalytic properties. The fabrication method of Bi2O2CO3 materials is known to be in various ways: hydrothermal synthesis, Low temperature solution synthesis and electro-chemical exfoliation. However, all of these methods have additional post-processing steps to the formation of Bi2O2CO3. In addition, in the case of hydrothermal and electrochemi-cal exfoliation methods to use electrodes, since the catalyst is in powder form, a binder is also required, which is not advantageous for industrial use. In this work, we could confirm spontaneously formed petal-shaped Bi2O2CO3 by using the immersion method in CO2 saturated KHCO3 electrolyte at room temperature and we studied the formation mechanism of Bi2O2CO3. Bismuth was known to be easily oxidized in acidic solution environment. However, anyone never reported what is happening in CO2 saturated the KHCO3 electrolyte (pH: 6.77) used as CO2 reduction electrolyte at room temperature. We confirmed that redox reactions, such as corrosion, occurred simul-taneously on the surface of bismuth in CO2 saturated the KHCO3 electrolyte. Bismuth atoms were oxidized to form BiO+ ions and electrons and simultaneously oxygen dis-solved in the electrolyte is reduced to from OH- ions. Subsequently BiO+ react with CO32- dissolved in the electrolyte to form Bi2O2CO3. We used these principles and we have suc-cessfully fabricated petal-shaped Bi2O2CO3 (named petal-BOC) on various substrates us-ing the immersion method in CO2 saturated 0.1M KHCO3 electrolyte at room temperature without some post-processing step. To confirm the possibility of use as electrochemical catalysis and photoelectrochem-cal catalysis, the EC CO2RR and the PEC CO2RR measurements were conducted in H-type two compartment electrochemical cell using petal-shaped BOC and bismuth thin film cathode as the working electrode, applying a constant potential in the specific ranges. In particular, it can be used as an electrochemical CO¬2 reduction catalyst for the production of formate by growing petal-shaped bismuth carbonate on a conductive Cu substrate. Compared with the bismuth thin film, the electrochemical active area increased by about 6.45 times, and the formate faradaic efficiency of 95.9% at -0.8 VRHE showed a result of 4.8 mA/cm2. In addition, it was confirmed that the light transmittance of bismuth subcarbonate grown on the TiO2/p-Si substrate by the same immersion method increased with longer immersion time of the bismuth thin film. Compared with the bismuth thin film, it exhibited high photoelectrochemical CO¬2reduction characteristics due to increased surface area and increased light transmittance. At -0.5VRHE, the formate faradaic efficiency was about 95.12% and the current density was 4.54 mA/cm2.

Design and Fabrication of Nanoscale Metal Interconnections for Transparent Deformable Electronic Devices

김동욱 포항공과대학교 일반대학원 2021 국내박사

As transparent displays and touch screens begin to be introduced to the public, the technology for transparent deformable electronic devices is attracting enormous attention as a next-generation electronic technology. Deformable optoelectronic devices, such as displays, solar cells, touch screens, and smart windows that maintain their functions under mechanical deformations have been developed, and various approaches to transparent deformable electrodes have been studied intensively. Despite these interests, transparent deformable nano- and micro-scale integrated interconnections that are easy to be patterned and positioned are receiving somewhat less attention. Since the most successful and feasible concept leading to deformable devices is linking rigid islands of active device components (transistor, light-emitting devices, photovoltaics, etc.) with deformable interconnections, developing transparent interconnections that can retain good electrical performance under high mechanical strain is highly required. In this work, I designed and fabricated three different types of transparent deformable nanoscale metal interconnections; (i) One-dimensional (1D) metal nanolines which were deposited on the flexible substrates by simple and reliable nanofiber (NF) photolithography, (ii) 1D wavy stretchable single metal NF which were individually positioned by the electrohydrodynamic (EHD) printing and metallized through room-temperature electroless plating, and (iii) Two-dimensional (2D) foldable and stretchable gold (Au) film hybrid electrodes which were composed of the anisotropic conductive ultrathin films (ACUFs) and the ultrathin Au film electrodes. These fabricated metal interconnections were not only electrically deformable but also optically transparent due to their nanoscale dimensions, and were able to be individually positioned and patterned in desired positions, shapes, and alignments. Also, all three deformable interconnections are fabricated by low-temperature processes and can easily expanded to large-scale production. The fabricated nanoscale metal interconnections were used as the interconnecting electrodes in the transparent and deformable field-effect transistors (FETs) array and the transparent electrodes of the deformable light-emitting devices.

단백질 다중 패널을 이용한 췌장암 진단 성능의 향상

최용환 포항공과대학교 일반대학원 2018 국내박사

높은 사망률과 무증상 성질로 인해 췌장선암(Pancreatic Ductal Adenocarcinoma, PDAC)의 조기 발견율은 매우 낮다. 대부분의 췌장선암 환자는 초기 진단 후 1 년 이내에 사망하고, 5년 생존율은 약 7 % 수준이다. 환자의 대부분이(약 80%) 초기 단계에서 증상이 나타나지 않아 예후가 좋지 않으며, 사실상 유일한 치료법은 외과적 수술을 통한 절제이다. 본 연구는 기존의 췌장선암 바이오마커인 CA19-9의 성능을 보완하여, 수술 가능한 환자군(췌장선암 1/2기)을 조기 발견할 수 있는 바이오마커 패널을 발굴하는 것을 목표로 진행하였다. 이에, 우리는 국내 5개 대형 병원(국립 암센터, 서울대학교병원, 삼성서울병원, 아산병원, 연세 세브란스 병원) 및 1개의 건강검진 센터(서울대학교병원 강남 건강검진 센터)에서 모은 1,000여개의 플라즈마 샘플을 수집하여 췌장선암 조기 진단용 바이오마커의 발굴 / 확인 / 검증 과정을 거쳤다. 우선, 문헌 파악 및 데이터베이스 검토를 통한 생물정보학적 방법(질병 네트워크 구축/분석, 가중치 부여, 우선순위 설정 등)을 이용하여 약 500개의 바이오마커 후보를, 세포 마이크로어레이 실험을 통해 약 500여개의 바이오마커 후보를 선정하여, 1,000여개의 바이오마커 후보군을 수립하였다. 이후 이 후보군에 대해 다중 반응 모니터링 질량 분석법(Multiple Reaction Monitoring Mass Spectrometry)을 이용하여, 실제 혈액에서의 검출 가능성 / 기기에서의 검출 안정성 / 병원에 따른 검출 안정성 등을 고려하여 18개의 바이오마커 마커 패널에 포함될 후보 단백질군을 선별하였다. 이 단백질들의 조합으로 만들어지는 마커 패널의 진단 성능은, 클러스터 서버를 이용한 기계학습(Machine Learning)법 중 서포트 벡터 머신(Support Vector Machine, SVM)을 이용하여 계산되었으며, 패널의 진단 성능과 실제 진단 제품으로 제작했을 경우의 경제성을 모두 고려할 때 3개 단백질로 이루어진 3-단백질 마커 패널이 가장 적절할 것으로 판단되었다. 다중 반응 모니터링 질량 분석법을 통한 각 혈중 단백질 계측 값으로 3-단백질 마커 패널의 진단 성능을 분석해 본 바, 다양한 3-단백질 마커 패널을 구축할 수 있었는데, 이 중 상용 항체로 구성이 가능한 CA19-9, LRG1, TTR로 이루어진 3-단백질 마커 패널의 경우, 기존의 췌장선암 진단 마커인 CA19-9를 단독으로 사용할 때 보다 진단 정확성(AUROC)과 진단 특이도가 90%일 때의 진단 민감도가 모두 10% 이상 유의미하게 상승한 것을 확인할 수 있었다. (진단 정확성은 DeLong의 방법을, 진단 민감도는 McNemar의 방법을 이용할 경우 모두 p-value < 0.05 수준) 이 성능은 다중 반응 모니터링 질량 분석법을 통한 혈중 단백질 계측만이 아닌, Roche社의 대형 진단 기기를 이용한 경우 계측 값을 사용했을 때와 효소면역분석법(Enzyme-Linked Immunosorbent Assay, ELISA)을 이용한 계측 값을 사용했을 때에도 진단의 성능은 재현되었으며, 그 통계적 유 의미성 또한 유지되었다. 또한, 해당 패널은 정상군과 췌장선암군의 구별 외에, 정상군과 조기 췌장선암군(1/2기), 다른 암종군(유방암, 대장암, 갑상선암)과 췌장선암군, 췌장 양성질환군과 췌장선암군, 기존의 췌장선암 바이오마커인 CA19-9가 정상이라고 판단하는 상황(CA19-9 < 37 U/ml)에서의 췌장선암 진단 성능 모두에서 기존의 췌장선암 바이오마커인 CA19-9 대비 유의미하게 향상된 진단 성능을 보여주었다. 이를 통해, 우리가 대규모 혈액 샘플에서 발굴하고 검증한 다중 단백질 마커 패널은 췌장선암의 조기 발견에 임상 적용 가능성을 가지고있다는 것을 확인할 수 있었다. The early detection rate of pancreatic ductal adenocarcinoma (PDAC) is very low due to its high mortality and asymptomatic nature. Most PDAC patients die within 1 year after initial diagnosis, and only 7% survives over 5 years. Most of PDAC patients (about 80%) have almost no symptoms at the early stages and this leads to poor prognoses. The only actual treatment is surgical resection. The purpose of this study is to find out the biomarker panel which can detect early stages of PDAC by complementing the existing PDAC biomarker, CA19-9. We had collected over 1000 plasma samples from 5 big hospitals in Korea (National Cancer Center, Seoul National University Hospital, Samsung Medical Center, Asan Medical Center, Yonsei Severance Hospital) and 1 health examination center (Seoul University Hospital Healthcare System Gangnam Center) to discover / verify / validate biomarkers for early diagnosis of PDAC First, we established 1000 biomarker candidates. About 500 biomarker candidates were screened by bioinformatic methods (construction and analysis of disease networks, weighting, priority setting, etc.) through literature review and database searching and about 500 more marker candidates were selected by cell microarray experiments. Using the multiple reaction monitoring mass spectrometry (MRM-MS), we filtered the biomarker candidate proteins to have potential diagnostic power and stability in detection. The diagnostic performance of the marker panel made by combining these proteins was calculated using Support Vector Machine (SVM) on cluster servers. Considering the diagnostic performance and the economic efficiency of the panel, we concluded that triple marker panel is the most appropriate. Analyzing the diagnostic performance of the triple marker panel by measuring the amount of each protein in blood using MRM-MS, we constructed various triple marker panels. In the case of the triple marker panel consisting of CA19-9, LRG1 and TTR, which can be composed of commercial antibodies, the diagnostic accuracy and diagnostic sensitivity (when specificity = 90%) were both increased by more than 10% of those of CA19-9 (DeLong's method for diagnosis accuracy and McNemar's method for diagnostic sensitivity, p-value < 0.05). This performance was confirmed not only by MRM-MS but also by Roche's machine and by the enzyme-linked immunosorbent assay (ELISA). This confirms that the triple-marker panel we have identified and verified in large-scale sample set has clinical applicability in the early detection of PDAC.

An Analysis on the Consumption Structure of Contemporary Popular Culture with Network Science

이정우 포항공과대학교 융합대학원 2022 국내석사

Globalization and the development of information technology have enabled people in different societies to share their culture and consume cultural products through digital devices. This social change has made contemporary popular culture to transcend the borders between countries and penetrate the daily lives of consumers. Our thesis focused on investigating which social factors affect the consumption structure of contemporary popular culture. We constructed a consumption network of mobile games between countries to reflect the characteristics of contemporary popular culture. Using Hofstede's cultural dimensions theory and Facebook's social connectedness index, we revealed cultural distance and social ties between countries play important roles in shaping the consumption structure.