포토리소그래피 검사 시스템의 이미지 분할을 위한 새로운 깊은 아키텍처

학위논문(박사) -- 서울대학교대학원 : 융합과학기술대학원 융합과학부(지능형융합시스템전공), 2021.8. 홍성수.In semiconductor manufacturing, defect detection is critical to maintain high yield. Typically, the defects of semiconductor wafer may be generated from the manufacturing process. Most computer vision systems used in semiconductor photolithography process inspection still have adopt to image processing algorithm, which often occur inspection faults due to sensitivity to external environment changes. Therefore, we intend to tackle this problem by means of converging the advantages of image processing algorithm and deep learning. In this dissertation, we propose Image Segmentation Detector (ISD) to extract the enhanced feature-maps under the situations where training dataset is limited in the specific industry domain, such as semiconductor photolithography inspection. ISD is used as a novel backbone network of state-of-the-art Mask R-CNN framework for image segmentation. ISD consists of four dense blocks and four transition layers. Especially, each dense block in ISD has the shortcut connection and the concatenation of the feature-maps produced in layer with dynamic growth rate for more compactness. ISD is trained from scratch without using recently approached transfer learning method. Additionally, ISD is trained with image dataset pre-processed by means of our designed image filter to extract the better enhanced feature map of Convolutional Neural Network (CNN). In ISD, one of the key design principles is the compactness, plays a critical role for addressing real-time problem and for application on resource bounded devices. To empirically demonstrate the model, this dissertation uses the existing image obtained from the computer vision system embedded in the currently operating semiconductor manufacturing equipment. ISD achieves consistently better results than state-of-the-art methods at the standard mean average precision which is the most common metric used to measure the accuracy of the instance detection. Significantly, our ISD outperforms baseline method DenseNet, while requiring only 1/4 parameters. We also observe that ISD can achieve comparable better results in performance than ResNet, with only much smaller 1/268 parameters, using no extra data or pre-trained models. Our experimental results show that ISD can be useful to many future image segmentation research efforts in diverse fields of semiconductor industry which is requiring real-time and good performance with only limited training dataset.반도체 제조에서 결함 검출은 높은 수율을 유지하는데 중요합니다. 전형적으로, 반도체 웨이퍼의 결함은 제조 공정에서 발생하고 있습니다. 반도체 포토리소그래피 공정 검사에 사용되는 대부분의 컴퓨터 비전 시스템들은 여전히 외부 환경 변화에 민감한 이미지 처리 알고리즘을 사용하고 있어서 검사 오류가 자주 발생하고 있습니다. 따라서, 이미지 처리 알고리즘의 장점과 딥 러닝의 장점을 융합하여 이 문제를 해결하려고 합니다. 이 논문에서 우리는 반도체 포토리소그래피 검사와 같이 훈련 데이터 세트가 제한된 상황에서 향상된 기능 맵을 추출하기 위해 이미지 분할 검출기(Image Segmentation Detector, 이하 ISD)를 제안합니다. ISD는 이미지 분할을 위한 최신 Mask R-CNN 프레임 워크의 새로운 백본 네트워크로 사용합니다. ISD는 4 개의 조밀한 블록과 4 개의 전환 레이어로 구성합니다. 특히, ISD의 각 조밀한 블록은 보다 컴팩트함을 위해 단축 연결 및 동적 성장률을 가지고 레이어에서 생성된 피쳐 맵을 결합하고 있습니다. ISD는 최근 적용하고 있는 전이 학습 방법을 사용하지 않고 처음부터 훈련합니다. 또한, ISD는 합성곱 신경망(Convolutional Neural Network, 이하 CNN)의 향상된 기능 맵을 추출하기 위해 우리가 설계한 이미지 필터를 통해 사전 처리된 이미지 데이터 세트로 훈련을 합니다. ISD의 설계 핵심 원칙 중 하나는 소형화로 실시간 문제를 해결하고 리소스에 제한이 있는 장치에 적용하는데 중요한 역할을 하게 합니다. 모델을 실증적으로 입증하기 위해 이 논문에서는 현재 운영 중인 반도체 제조 장비에 내장된 컴퓨터 비전 시스템에서 획득한 실제 이미지를 사용합니다. ISD는 가장 일반적인 성능 측정 지표인 평균 정밀도에서 최첨단 백본 네트워크 보다 일관되게 더 나은 성능을 얻습니다. 특히, ISD는 베이스 라인으로 삼은 DenseNet 보다 파라미터들이 4배 더 적지만, 성능이 우수 합니다. 우리는 또한 ISD가 Mask R-CNN 백본 네트워크로 주로 사용하는 ResNet 보다 268배 훨씬 더 적은 파라미터들을 가지고, 추가 데이터 또는 사전 훈련된 모델을 사용하지 않고, 성능에서 비슷하거나 더 나은 결과를 얻을 수 있음을 관찰합니다. 우리의 실험 결과들은 ISD가 제한된 훈련 데이터 세트만으로 실시간 및 우수한 성능을 요구하는 반도체 산업의 다양한 분야들에서 많은 미래의 이미지 분할 연구 노력에 유용할 수 있음을 보여줍니다.Chapter 1. Introduction １ 1.1. Background and Motivation ４ Chapter 2. Related Work １２ 2.1. Inspection Method １２ 2.2. Instance Segmentation １６ 2.3. Backbone Structure ２４ 2.4. Enhanced Feature Map ３５ 2.5. Detection Performance Evaluation ４７ 2.6. Learning Network Model from Scratch ５０ Chapter 3. Proposed Method ５２ 3.1. ISD Architecture ５２ 3.2. Pre-processing ６３ 3.3. Model Training ７１ 3.4. Training Objective ７３ 3.5. Setting and Configurations ７５ Chapter 4. Experimental Evaluation ７８ 4.1. Classification Results on ISD ８１ 4.2. Comparison with Pre-processing ８５ 4.3. Image Segmentation Results on ISD ９４ 4.3.1. Results on Suck-back State ９４ 4.3.2. Results on Dispensing State １０４ 4.4. Comparison with State-of-the-art Methods １１３ Chapter 5. Conclusion １２１ Bibliography １２７ 초록 １４６박

Factors affecting pouch-related outcomes after restorative proctocolectomy.

PURPOSES: Restorative proctocolectomy (RPC) with ileal pouch anal anastomosis (IPAA) is the procedure of choice for patients with familial adenomatous polyposis (FAP) and ulcerative colitis (UC) despite morbidities that can lead to pouch failure. We aimed to identify factors associated with pouch-related morbidities. METHODS: A retrospective analysis of patients who underwent RPC with IPAA was performed. To investigate the factors associated with pouch-related morbidities, patients' preoperative demographic and clinical factors, and intraoperative factors were included in the analysis. RESULTS: A total of 49 patients with UC, FAP, and colorectal cancer were included. Twenty patients (40.8%) experienced leakage-related, functional, and/or pouchitis-related morbidities. Patients with American Society of Anesthesiologists (ASA) grade 2 or 3 had a higher risk of functional morbidity than those with grade 1. Intraoperative blood loss exceeding 300.0 mL was associated with an increased risk of pouchitis-related morbidity. CONCLUSIONS: Our study demonstrated associations of higher ASA grade and increased intraoperative blood loss with poor functional outcomes and pouchitis, respectively.ope

The number of retrieved lymph nodes needed for accurate staging differs based on the presence of preoperative chemoradiation for rectal cancer

The aim of this study is to investigate if retrieval of 12 lymph nodes (LNs) is sufficient to avoid stage migration as well as to evaluate the prognostic impact of insufficient LN retrieval in different treatment settings of rectal cancer, particularly in the case of preoperative chemoradiotherapy (pCRT).The data of all patients with biopsy proven rectal adenocarcinoma who underwent curative surgery between January 2005 and December 2012 were analyzed. Univariate and multivariate analyses for oncologic outcomes were performed in LN metastasis or no LN metastasis (LN-) group. Subgroup analyses were performed according to whether a patient had received pCRT.A total of 1825 patients were enrolled into the study. The maximal Chi-square method revealed the minimum number of harvested LNs required to be 12. Univariate and multivariate analyses found LNs?≥?12 to be an independent prognostic factor for both overall survival (OS) (hazard ratio [HR] = 0.5, 95% confidence intervals [CIs]: 0.3-0.8; P = 0.002) and disease-free survival (DFS) (HR = 0.6, 95% CI: 0.4-0.7; P?<?0.001) in the LN- group. In the LN- group, LNs?≥?12 continued to be a significant prognostic factor both for OS and DFS in the subgroup of patients who did not undergo pCRT. However, in the subgroup of the LN- patients who underwent pCRT, LN?≥?8 was significant for DFS and OS.Retrieval of LNs?≥?12 and LNs?≥?8 should be achieved to obtain accurate staging and optimal treatment for the non-pCRT and pCRT groups in rectal cancer, respectively.ope

Do audit fees and audit hours influence credit ratings?: A comparative analysis of Big4 vs Non-Big4

We examine the relationship between credit ratings / changes and audit fees (hours) for Big4 and Non-Big4 firms. Audit fee (hours) may be considered as a default risk metric for credit ratings agencies. However, firms audited by Big4 are larger, better performing and operate with lower leverage compared to firms followed by Non-Big4. Therefore, the association between audit fee (hours) may be different for firms followed by Big4 and Non-Big4 audit firms. We find that there is a negative association between audit fees and credit ratings for firms followed by Big4 audit firms. However, we find an insignificant relation for firms followed by Non-Big4. We conjecture the different association due to the Big4 firms having more robust accounting procedures; Big4 firms must offer competitive audit fees because they are engaged in fierce competition with other Big4 firms. Moreover, Big4 and Non-Big4 firms have different relationships with their clients because Non-Big4 firms are more income dependent on their clients. Using a sample of 1,717 firm–year observations between 2002 and 2013, we establish a relation between audit fees in period t and credit ratings in period t+1, for firms followed by Big4 auditors. We do not find a significant relation for firms followed by Non-Nig4 firms, suggesting that credit ratings agencies perceive audit fee differently for Big4 and Non-Big4 firms. Client firms followed by Big4 auditors that experience a credit rating change in period t+1 pay lower audit fees in period t compared to firms that do not experience a credit rating change. Our additional analysis suggests a different association between firms audit fees and firm performance for firms that experience a credit rating increase and decrease. Firms that experience a credit ratings increase in period t+1 have strong performance and lower audit fees in period t. On the other hand, firms that experience a credit rating decrease have weak financial performance and negative audit fees compared to firms that do not experience a credit ratings change. Our results suggest that audit fees combined with financial performance influence a credit ratings agency' perception of default risk

여성 뇌졸중 환자를 돌보는 남편 간호자의 부담감과 건강 관련 삶의 질

학위논문 (석사)-- 서울대학교 대학원 : 간호학과, 2012. 2. 박연환.뇌졸중은 장기적인 간호를 요하는 질환으로 뇌졸중 환자 간호는 대부분 가족에 의해 시행되며 이들을 돌보는 가족 간호자의 부담감은 높은 편이다. 가족 중 배우자는 가장 비율이 높은데 배우자는 다른 가족 구성원에 비해 환자 간호에 대한 부담감이 높으며, 뇌졸중 환자를 돌보는 배우자는 대부분 노인으로 스스로의 건강 문제까지 가지고 있다. 남편 간호자는 여성과 달리 스스로의 건강 관리의 질이 떨어지며 가사일에도 어려움을 겪어 부담감이 높을 수 있으나 이에 대한 연구는 부족하다. 따라서 본 연구는 여성 뇌졸중 환자를 돌보는 남편 간호자의 부담감과 건강 관련 삶의 질과의 관계를 파악하기 위해 시행되었다. 연구 대상자는 2011년 2월~4월 사이 서울에 위치한 일개 종합병원 신경과 외래에 내원한 뇌졸중 환자와 주 간호자인 65세 이상의 남편 간호자로 최종 121쌍이 연구되었다. 남편 간호자의 부담감은 63.3±9.8점으로 보통보다 약간 낮은 상태였으며 부담감의 하위 항목 중 보호 활동의 결과로 생기는 부담감이 가장 높았다. 부담감이 높은 문항은 대부분 본인이 보호를 수행하는 데에 있어서의 부담감에 속하였다. 또한 부담감의 문항 중 환자와의 관계가 나아지기를 원한다는 정도가 높은 집단이 정도가 낮은 집단에 비해 부담감이 더 높았다. 남편 간호자의 간호 활동 시간은 평균 58.5±5.5분/일이었으며 가장 많이 하는 간호 활동은 이동(움직이는 것) 도와주기(51.2%), 식사 보조(50.4%), 환자의 약물 복용 보조(50.4%)였다. 간호 활동의 일 평균 소요 시간은 식사 보조(11.3분/일), 식사 준비(11.2분/일), 환자의 교통 수단(버스, 택시, 지하철 등) 이용 보조(11.2분/일)의 순서로 소요되었다. 부담감에 영향을 미치는 요인은 남편 간호자의 우울(B=.805, p=.000), 뇌졸중 환자의 인지 기능(B=-.179, p=.014), 뇌졸중 환자의 일상 생활 의존도(B=1.869, p=.008), 그리고 남편 간호자의 간호 활동 시간(B=.039, p=.013).으로 나타났다. 남편 간호자의 건강 관련 삶의 질 정도는 신체적 건강과(47.49점) 정신적 건강(47.33점) 모두 good grade로 비슷하게 나타났으며 부담감은 신체적 건강 (r=-.566, p<.01) 과 정신적 건강(r=-.565, p<.01)에 모두 음의 상관 관계를 보였다. 본 연구 결과를 통해 여성 뇌졸중 환자를 돌보는 남편 간호자의 부담감 감소를 위해서는 남편 간호자에게 정서적 상담과 자조 집단과의 모임이 필요하며 뇌졸중 환자의 일상 생활 의존에 대한 사회적 지지가 필요함을 제언한다. 또한 남편 간호자의 가사일에 대한 교육과 지지가 제공되어야 하며 뇌졸중으로 인한 인지 기능 저하의 특성과 함께 이에 대한 대처 방법을 교육하는 것이 뒷받침되어야 하겠다. 또한 여성 뇌졸중 환자를 돌보는 남편 간호자의 간호 활동 종류에 대한 정확한 도구의 개발과 함께 뇌졸중의 진단명, 뇌졸중 환자의 증상 및 우울 정도, 다른 가족의 지지 여부 그리고 다른 가족의 간호 역할 배분 등에 따른 부담감에 대하여 추후 연구가 필요하겠다.Stroke is a disease which needs long term care and most family members care their stroke patients so that family caregivers burden is high. Almost family caregivers are spouses and spouses burden is much higher than other family caregivers. Stroke patients spouses are almost elders so they have many disease problems. In male spouses, they are relatively poor health status and they are different from female spouses, however there are seldom studies about stroke patients male caregivers. The purpose of this study is to investigate caregiver burden and health related quality of life in male spouses who care female stroke patients. The subjects of the final analysis are 121 stroke patients and their male spouses who visited the neurology outpatients department in a tertiary hospital located in Seoul between February and April in 2011. Male spouses are primary caregivers and over 65 years. The data was analyzed with descriptive statistics, t-tests, chrobach a, oneway ANOVA, Scheffes method and pearsons correlation using SPSS(ver 18.0). The mean score of caregiver burden is 63.3±9.8. The mean score(standardized score) of burden to patients is 14.9±3.6 (2.13±0.50), burden to care is 27.7±3.3(2.30±0.27) and burden to sacrifice of personal life is 20.7±3.6(2.59±0.54). The average of caregiver activity time per day is 58.5±5.5min. The most caregiver activities are Ambulation(51.2%), Eating(50.4%), Medication(50.4%), Bathing(47.9%) and Dressing(42.9%). The most time required activities are Eating(11.3min/day), Food preparation(11.2min/day), Using transportation(11.2min/day), Walking distance(11.1min/day) and Housekeeping(11.0min/day). The related factors of caregiver burden are caregivers depression(B=.805, p=.000), stroke patients cognitive status(B=-.179, p=.014), stroke patients dependencies(B=1.869, p=.008) and caregivers activity time(B=.039, p=.013). Caregivers health related quality of life are physical health and mental health. The mean score of physical health is 47.49 and mental health is 47.33. Both mental and physical health are good grades. Caregiver burden is related with physical health(r=-.566, p<.01) and mental health(r=-.565, p<.01). The conclusions in this study are below. In conclusion, male spouses caregiver burden is moderate and the score of burden to sacrifice of personal life is the highest. The related factors of caregiver burden is caregivers depression, stroke patients cognitive status, stroke patients dependencies and caregivers activity time, whereas caregivers subjective health status and relationship are not affected to caregiver burden. Male spouses physical health and mental health are moderate. Caregiver burden is negative correlation with health related quality of life. To reduce male spouses caregiver burden, emotional support and activation of self-help group meeting are needed to decrease caregivers depression. Social supports of stroke patients dependencies, education of housework to male spouses are also required. Moreover it is needed that nursing education about the characteristics of stroke patients cognitive impairment and how to cope with reduced cognitive function to the state. Further studies are necessary to validate male spouses caregiver burden and to develop the nursing activities.Maste

An Empirical Study on the Effectiveness of Regional Innovation Cluster Policy: the Firm`s Character and Network Activities for Innovation Using of Social Capital

지역클러스터 육성 정책의 성패여부는 클러스터 내 기업들이 얼마나 활발한 혁신활동을 하느냐에 달려 있다. 혁신활동의 결과, 기업은 지속적으로 경쟁력을 확보하고, 인근 지역은 이를 통하여 경제적 발전을 추구하며, 국가적으로는 산업발전을 꾸준히 지속시키는데 있다. 경쟁 환경이 글로벌화 되면서, 개별기업이 기술혁신에 필요한 모든 것을 보유하기란 현실적으로 불가능하다. 클러스터란 일정한 지리적 공간 내에 기업, 대학, 연구소, 공공기관 등의 집적을 통한 이들 기관과의 네트워크와 상호작용으로 기업의 경쟁력을 강화하는 것이다. 기관들의 지리적 집적이 하드웨어적인 인프라구축 이라면 클러스터 내 구성원들의 관계를 이어주는 가교역할의 소프트웨어적 구축으로 사회적자본이 필요하다. 본 연구에서는 클러스터 내에 구축된 사회적 자본이 기업의 혁신활동을 이어주는 역할을 할 것 이라는 가설에서 출발하였다. 실증분석결과 중견기업 이상 규모의 기업은 구성원 간 사회적 자본인 신뢰변수가 높다고 인식하고 있는 반면, 규모가 작은 기업은 그렇지 않았다. 각 구성원 간의 관계영역에서는 규모가 작은 기업은 대학, 연구소와의 협력활동을 추구하려는 경향이 있지만 중견기업 이상의 규모가 큰 기업은 그렇지 못했다. 공공기관 간의 관계에서도 동일한 결과를 보여주고 있으며, 혁신을 위한 활동에서는 오히려 규모가 작은 기업이 혁신에 보다 적극성을 보여주고 있다. 이런 결과를 볼 때, 연구가설에서 사용한 신뢰, 규범, 목표공유 등의 사회적 자본이외에 지식, 정보 및 노하우 등 클러스터가 가지는 특정 성격에서 배태(embeddendess)되는 클러스터 고유의 사회적인 자본이 구축되어야 한다. 이를 위해서 기존의 중소기업 육성뿐 아닌, 사회적인 자본창출에 보다 적극적인 중견기업 육성정책수단도 강구할 필요가 있다. The success and failure of the clusters pursued by government depends on how much their members interact with one another. Clusters are currently being pursued by the government and cover a diverse spectrum, ranging from export complexes to R&D institutes. Regional and national economic development is expected due to the effectiveness of fostering clusters. Each firm is pursing innovation using of face-to-face contact. social capital in the form of trust, norms, and shared goals facilitates the sharing of knowledge and informahon when people meet. This paper shows that upper structure, which mean the role of social capital and the relationship of each establishment is not performed. Medium size firms feel more trust than small firms. However, small firms have stronger to relationships with establishments like universities, research institutes, and public agencis than medium firms. Small firms are more proactive than medium ones with regard to innovative activities. According to the empirical results, boasting the role of social capital for continuing interaction among each actor for innovation is necessary. Policy support for dusters should change from low structure clusters to upper structure clusters

명목소득 타겟팅전략과 그 운용준칙에 관한 일고찰

학위논문(석사)--서울대학교 대학원 :경제학부 경제학전공,1997.Maste

일본산 수입식품 안전성 규제에 따른 무역변화에 대한 연구

학위논문 (석사)-- 서울대학교 국제대학원 : 국제학과, 2015. 2. 안덕근.Japan relies heavily on import products including semiconductor, vehicles, computers, and most importantly the daily agricultural products. They also heavily rely on the export commodities for their economic growth and stability. Among many traded commodities, Japans food sectors consist of seafood, vegetable, and meat products. Of all the food products being exported, Japan is a leading exporter of seafood products, with the amount totaling up to about 40% of all food exports. However, since the Fukushima accident, the atmosphere in export has been changing. The impact of Japans earthquake and tsunami has left serious damage in many parts of Japan. It has made physical damage amounting up to $195 billion to$305 billion. 23,000 people went missing or were reported killed. The main side-effect led to Fukushima Dai-ichi nuclear power plant accident. KOTRA reported that the Japan production companies are facing 20 to 50% decrease in manufacturing products, depending on each commodities, due to the Japans Dai-ichi nuclear plant incident. And there were more than 400,000 damaged buildings. It has been three years and eight months since the incident of the Japans earthquake and Fukushima Dai-ichi nuclear power plants accident, however, the worrisome eyes towards the food supplies being produced in Japan is growing bigger as the time pass. This is mainly because there are continuous reports stating that the leakage from nuclear power plant has not stopped and is still on going. Japan has been showing trend of decrease in the trade volume of agricultural and seafood products since the 2011 Fukushima power plant accident. The Japanese government are aware of the possible danger in their food products. They have announced that fishery activities should not resume in the area of Fukushima prefecture. Naturally, many countries, including Canada, China, European Union, Korea, and United States has raised their surveillance levels on the imported food from Japan. Japan has been requesting their trading partners to remove any discriminating policies and unreasonable increase in surveillance level of their food imports. It is true that in the previous studies it has been proven that the policies on food safety level of one country does impact the amount of trade volume of agricultural and seafood products. However, is the phenomenon of export volume decrease in Japan also due to the policy imposed on the Japanese food imports from neighboring countries? If it is, is it significant enough to blame the decrease in export volume on the regulations of the other countries? The policies imposed on Japanese imported goods vary from one country to another, some having stricter restrictions as opposed to others not having any sort of barriers. This study will find to see if the strictness of the policy imposed due to the Fukushima power plant accidents has significant impact on the change in export volume of Japanese agricultural and seafood commodities.ABSTRACT i TABLE OF CONTENTS iii LIST OF TABLES AND FIGURES iv LIST OF ABBREVIATIONS v I. Introduction 1 1) Background in Japans Dai-ichi nuclear plant incident 2 2) Japans Export Food Safety 4 3) Objective 6 II. Regulations 7 1) Japans governmental intervention 7 2) Regulations between Japan and other countries 8 2.1 Korea and Japan 9 2.2 China and Japan 13 2.3 United States of America and Japan 14 2.4 Canada and Japan 16 2.5 European Union and Japan 17 III. Literature Review 19 1) Gravity Model 19 2) Customers Survey on Food Safety 20 IV. Analysis on the Impact of Regulations on Export of Agricultural and Seafood Supplies in Japan 21 1) Gravity Model 22 2) Empirical Model and Data Collection 23 3) Empirical Results 25 V. Conclusion and Recommendations 29 VI. References 31 국문초록 34Maste