ROS2기반의 자동차 사이버 시스템을 위한 기능적/시간적 정확성을 보장하는 실시간 시뮬레이션 기법

학위논문 (석사) -- 서울대학교 대학원 : 공과대학 컴퓨터공학부, 2021. 2. 이창건.This dissertation proposes an approach for functionally and temporally correct simulation of cyber system based on ROS2 framework. In the previous work, the simulation approach was proposed that overcomes the limitations, which only guaranteeing the functional correctness of the existing simulation approach by guaranteeing the temporal correctness and simultaneously performs the task efficiently by reordering jobs. Recognizing that the ROS2 cyber system differs from the traditional automotive cyber systems, this dissertation can be applied to the ROS2 cyber system while maintaining the key idea of the previous simulation approach. In the proposed approach, a system model for ROS2 cyber system is defined. Based on this, the cyber systems schedule is predicted, and a precedence relationship graph is generated so that the existing simulation technique can be applied. The proposed method measures the simulation capacity, together with other simulation algorithms, through a randomly generated workload, and it is shown that the proposed approach has the highest simulation capacity in a single core simulator. Therefore, the existing functional/ temporally correct simulation approach can be applied to the cyber system of automotive system based on ROS2 framework, and by utilizing this, it is possible to correctly and effectively simulate the ROS2 cyber system.본 논문은 ROS2를 기반으로 설계된 자동차 사이버 시스템을 기능적/시간적으로 정확하게 시뮬레이션하는 방법론을 제안한다. 앞선 연구에서는 기존의 시뮬레이션 기법들의 기능적인 정확성만 보장하는 문제에서 발생하는 한계점을 극복하고 동시에 효율적으로 작업을 수행하는 시뮬레이션 기법이 제안되었다. ROS2 기반의 자동차 사이버 시스템에서는 기능 수행의 행태가 기존의 자동차 사이버 시스템과는 다르다는 것을 인지하여 본 논문에서는 앞선 연구에서 제안하는 시뮬레이션 기법의 핵심 아이디어가 유지되면서 ROS2 기반의 자동차 사이버 시스템에 적용이 될 수 있도록 시뮬레이션 기법을 제안한다. 제안하는 방법에서는 ROS2 스케줄링을 고려한 시스템 모델을 정의하고 이를 기반으로 실제 사이버 시스템의 스케줄을 예측하고 선행 관계 그래프를 생성하여 기존의 시뮬레이션 기법이 그대로 적용될 수 있도록 한다. 제안하는 방법은 임의적으로 생성된 워크로드를 통해 다른 시뮬레이션 알고리즘과 함께 시뮬레이션 용량을 측정하고, 제안하는 방법이 싱글코어 시뮬레이터에서 가장 높은 시뮬레이션 용량을 가지는 것을 보인다. 따라서, 기존의 기능적/시간적으로 정확한 시뮬레이션 기법이 ROS2 기반의 자동차 사이버 시스템에서도 적용이 가능하며, 이를 활용하여 기존의 자동차 사이버 시스템뿐만 아니라 ROS2 기반의 자동차 사이버 시스템을 효과적으로 시뮬레이션 할 수 있다.1 Introduction 1 1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Backgrounds 4 2.1 Overview of Functionally and Temporally Correct Simulation . . . 4 2.2 ROS2 Scheduling . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3 Proposed Approach 10 3.1 System Model for ROS2 Cyber System . . . . . . . . . . . . . . . 10 3.2 Offline Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.3 Online Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4 Evaluation 18 4.1 Experimental Setup . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.2 Simulation Results . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5 Conclusion 21 References 23Maste

Mycobacterium tuberculosis에서 유래한 MazE2의 DNA binding에 대한 구조적, 기능적 연구

학위논문 (석사)-- 서울대학교 대학원 약학대학 약학과, 2017. 8. 이봉진.Mycobacterium tuberculosis was first discovered by Robert Koch in 1882 and is a human infectious strain that causes lung disease through the respiratory tract. M. tuberculosis differs from ordinary bacteria in that it has thick membranes on the cell surface and does not stain Gram stain. However, when stained with Ziehl-Neelsen, it is difficult to decolorize by acid, alcohol and boiling, and this property is called acid-fast. Gram staining is negative, but they do not have external membranes and are classified as acid-fast gram-positive bacteria. Treatment of patients infected with M. tuberculosis is mainly medication. Isoniazid, rifampin, and pyrazinamide are used, and streptomycin is also used. Mycobacterium tuberculosis has the largest number of Toxin-Antitoxin system pairs among bacteria. The Toxin-Antitoxin system is classified into six types according to antitoxin properties. The target protein Rv0660c of this study is MazE, an antitoxin of MazEF system, which is one of Type2 Toxin-Antitoxin system. The Toxin-Antitoxin system plays a role in inhibiting the growth of bacteria or leading to death by external stimuli-activated toxins. Antitoxin normally binds to toxin and inhibits the activity of toxin. but it breaks down in extreme situations. Thus, dissociated toxin induces growth inhibition and death. This also induces latency and lowers susceptibility to antibiotics. We overexpress the N1-44 construct of Rv0660c to characterize the tertiary structure of this Rv0660c protein. His-tagged Rv0660c protein was purified using Immobilized Metal Affinity Chromatography (IMAC), and the His-tag was removed through thrombin cutting to further increase the protein purity. As a result, the crystal could be made and the structure could be obtained with a high resolution of 1.69 Å. The DNA binding experiments of Rv0660c were carried out by NMR and EMSA. Rv0660c was labeled with 13C and 15N isotopes. Heteronuclear multidimensional NMR spectra were measured and backbone assignments were made through HNCO, HNCA, HNCACO, HNCOCA, HNCOCACB and HNCACB spectra. The TALOS program was used to predict the secondary structure and identify the parts which interact DNA through DNA titration. We confirmed the binding of Rv0660c with DNA in vitro from Electrophoretic Mobility Shift Assay (EMSA).I. Introduction 1 1.1 Structure Based Drug Design (SBDD) 1 1.2 Characteristics of Mycobacterium tuberculosis 2 1.3 Epidemiology of Mycobacterium tuberculosis 2 1.4 Toxin–Antitoxin System 3 1.5 Characteristics of Rv0660c 4 1.6 Purpose of the study 5 Ⅱ. Materials and Methods 6 2.1 Materials 6 2.1.1 Reagents 6 2.1.2 Apparatus 7 2.2. Methods 7 2.2.1 Cloning of target protein 8 2.2.2 Protein over-expression and purification 9 2.2.3 Crystallization 10 2.2.4. X-ray data collection and structure determination 11 2.3 Structural and Functional studies by NMR spectroscopy 11 2.3.1 NMR data collection 12 2.3.2 Backbone assignment . 12 2.3.3 Secondary structure prediction based on TALOS 13 2.3.4 DNA synthesis and preparation 13 2.4 Electrophoretic Mobility Shift Assay (EMSA) 14 Ⅲ. Result 15 3.1 Protein preparation 15 3.1.1 Cloning, overexpression and purification 15 3.1.2 Crystallization 18 3.2 Crystal structure of Rv0660c1-44 19 3.3 NMR studies of 15N or15N-13C labeled Rv0660c1-44 20 3.3.1 2D 1H-15N HSQC 20 3.3.2 Sequential backbone assignment 21 3.3.3 Predicted secondary structure of Rv0660c1-44 22 3.4 Functional study 24 3.4.1 Protein-DNA binding 24 3.4.2 Comprehensive result of protein-DNA binding 27 3.4.3 Electrophoretic Mobility Shift Assay (EMSA) 29 Ⅳ. Disussion 30 Ⅴ. Referenece 31 국문초록 35Maste

'기업의 사회적 책임' 국제규격 (ISO 26000)의 동향과 고찰

기업의 사회적 책임(Corporate Social Responsibility (CSR))이 최근 기업경영의 화두가 되고 있으며, 국제표준화기구(Organization for International Standardization (ISO))에서도 기업의 사회적 책임에 대한 국제적 표준 제정 작업을 서두르고 있다. 본 논문에서는 CSR의 태동과정을 살펴보고, CSR이 담고 있는 근본적인 개념을 먼저 소개한다. ISO는 CSR에 관련된 표준을 ISO 26000으로 명명할 예정이며, ISO 26000에 담겨질 내용은 어떤 것들이 있을까에 대하여 예측하여 설명하기로 한다. 지구촌은 급격히 국제화되어 가고 있으며, 이러한 국제적 표준이 기업의 경영활동에 주는 영향을 막대할 것으로 보인다. 따라서 기업들은 이러한 국제적 표준에 대비한 표준경영을 하루 빨리 준비할 때이다. 이 글이 ISO 26000에 관심을 가지고 있거나 준비하는 조직에게 유용한 경영정보를 제공할 수 있기를 기대한다

- 지니계수와 실업률을 중심으로-

학위논문(석사) -- 서울대학교대학원 : 사회과학대학 경제학부, 2022.2. 김영식.본 연구는 경기변동에 따른 정부의 정책효과를 경기변동지수인 실업률, 소비자물가상승률, 경제성장률과 소득불평등의 정도를 측정할 수 있는 지니계수를 통해 분석하고 정리해본다. 본 연구에서는 지니계수를 세전, 세후로 분리하여 각각의 연도별 차이를 구한 뒤, 이를 정부의 조세 정책에 의한 소득불평등 개선도로 측정하여 이를 분석대상으로 하였다. 주요 분석 결과로는 실업률이 올라갈수록 즉 경기가 악화될 때 소득 불평등의 정도는 정부의 조세정책을 통한 개입 전보다 개입 후가 더욱 좋지 못한 것으로 나타났다. 이는 실업률의 변동으로 살펴본 경기변동에 따른 정부의 개입이 경기 회복과 악화의 시점에 따라 개입 의도와는 다르게 소득불평등을 되려 악화시키는 결과를 초래할 수 있다고 정리할 수 있다.This study analyzes and summarizes the government's progressive tax policy effects on income inequality which can measure by the Gini coefficient through economic indexes (unemployment rate, inflation rate, economic growth rate). In this study, the Gini coefficient was separated into pre-tax and post-tax categories to find the difference for each year, and this was measured as the improvement in income inequality by the government's tax policy, and this was used as an analysis target. The result of the main analysis, the unemployment rate rises, that is, when the economy deteriorates, the degree of income inequality is worse after the intervention than before the intervention through the government's tax policy. This can be summarized that government’s intervention in response to economic fluctuations, which was examined by fluctuations in the unemployment rate, could lead to aggravating income inequality differently from the intention of the intervention, depending on the timing of economic recovery and deterioration.1. 서 론 1 2. 선행연구 3 3. 연구방법 설계 7 3.1 연구 모형 7 3.2 정부 정책효과의 측정 8 3.3 경기변동지수 12 3.4 통제변수 (경상조세 실부담률) 14 4. 실증분석 결과 18 5. 결 론 20 참고문헌 22 Abstract 24 표 목차 [표2-1] 4 [표2-2] 5 [표3-1] 8 [표3-2] 10 [표3-3] 13 [표3-4] 17 그림 목차 [그림3-1] 11 [그림3-2] 11 [그림3-3] 12석

부동산업의 경영혁신: 6시그마 방법론을 활용한 사례 연구

마이크로소프트회사의 Bill Gates(l999) 회장은 비즈니스는 다가올 10 년 동안에 지난 50년 보다 훨씬 더 큰 변화를 겪게 될 것이다라고 말하였다. 그의 말처럼 지금은 기업 환경이 급속히 변화하고 있으며, 시장의 글로벌화와 경영패러다임의 변화는 개별기업 뿐만 아니라 한국산업 전체에 새로운 전략적 대응을 요구하고 있다. 부동산 시장 역시 외국계 부동산기업이 지식과 자본을 앞세워 국내에 이미 진출해 있는 실정이나, 다른 업종에 비하여 국내 부동산기업은 경영패러다임의 변화에 대한 적응이 훨씬 느린 편이다. 사업 추진의 전문화와 업무프로세스의 표준화가 미흡한 우리나라 부동산 기업이 이러한 시장 변화를 좌시하고만 있거나 선진부동산 시스템 도입을 등한시 하는 경우 경쟁력이 뒤쳐질 수밖에 없는 상황에 직면하게 될 것이다. 본 논문은 국내 부동산시장의 토양위에 선진부동산 시스템을 도입하여 경영체질을 개선하고 경쟁력을 강화하고자 노력하고 있는 ERA-Korea사를 조사 기업으로 선정하여, 우리나라 부동산 기업의 경영활동에 경영패러다임의 변화를 적응시키고, 경영품질을 높이기 위하여 과학적 경영혁신 기법인 6시그마 경영혁신 기법을 적용하여 봄으로써 부동산 기업에 새로운 경영품질관리 모델을 제시하고 궁극적으로 국내 부동산기업의 경쟁력 강화를 위한 부동산 경영의 과학화 방법을 연구하는데 그 목적이 있다

Patient-specific virtual three-dimensional surgical navigation for gastric cancer surgery: A prospective study for preoperative planning and intraoperative guidance

Introduction: Abdominal computed tomography (CT) can accurately demonstrate organs and vascular structures around the stomach, and its potential role for image guidance is becoming increasingly established. However, solely using two-dimensional CT images to identify critical anatomical structures is undeniably challenging and not surgeon-friendly. To validate the feasibility of a patient-specific 3-D surgical navigation system for preoperative planning and intraoperative guidance during robotic gastric cancer surgery. Materials and methods: A prospective single-arm open-label observational study was conducted. Thirty participants underwent robotic distal gastrectomy for gastric cancer using a virtual surgical navigation system that provides patient-specific 3-D anatomical information with a pneumoperitoneum model using preoperative CT-angiography. Turnaround time and the accuracy of detecting vascular anatomy with its variations were measured, and perioperative outcomes were compared with a control group after propensity-score matching during the same study period. Results: Among 36 registered patients, 6 were excluded from the study. Patient-specific 3-D anatomy reconstruction was successfully implemented without any problems in all 30 patients using preoperative CT. All vessels encountered during gastric cancer surgery were successfully reconstructed, and all vascular origins and variations were identical to operative findings. The operative data and short-term outcomes between the experimental and control group were comparable. The experimental group showed shorter anesthesia time (218.6 min vs. 230.3 min; P=0.299), operative time (177.1 min vs. 193.9 min; P=0.137), and console time (129.3 min vs. 147.4 min; P=0.101) than the control group, although the differences were not statistically significant. Conclusions: Patient-specific 3-D surgical navigation system for robotic gastrectomy for gastric cancer is clinically feasible and applicable with an acceptable turnaround time. This system enables patient-specific preoperative planning and intraoperative navigation by visualizing all the anatomy required for gastrectomy in 3-D models without any error. Clinical trial registration: Clinicaltrials.gov, identifier NCT05039333.ope

Chylous Ascites After Gastric Cancer Surgery: Risk Factors and Treatment Results

Purpose: Although chylous ascites is a frequent complication of radical gastrectomy for gastric cancer, proper diagnostic criteria and optimal treatment strategies have not been established. This study aimed to identify the clinical features of chylous ascites and evaluate the treatment outcomes. Materials and methods: We retrospectively analyzed the data of patients who underwent radical gastrectomy between 2013 and 2019. Diagnosis was made when milky fluid or elevated triglyceride levels (≥100 mg/dL) appeared in the drains without a preceding infection. The clinical features, risk factors, and treatment outcomes were assessed according to the initial treatment modalities for fasting and non-fasting groups. Results: Among the 7,388 patients who underwent radical gastrectomy for gastric cancer, 156 (2.1%) experienced chylous ascites. The median length of hospital stay was longer in patients with chylous ascites than in those without (median [interquartile range]: 8.0 [6.0-12.0] vs. 6.0 [5.0-8.0], P<0.001). Low body mass index (adjusted odds ratio [aOR]=0.9; P<0.001), advanced gastric cancer (aOR=1.51, P=0.024), open surgery (reference: laparoscopic surgery; aOR=1.87, P=0.003), and extent of surgical resection (reference: subtotal gastrectomy, total gastrectomy, aOR=1.5, P=0.029; proximal gastrectomy, aOR=2.93, P=0.002) were associated with the occurrence of chylous ascites. The fasting group (n=12) was hospitalized for a longer period than the non-fasting group (n=144) (15.0 [12.5-19.5] vs. 8.0 [6.0-10.0], P<0.001). There was no difference in grade III complication rate (16.7% vs. 4.2%, P=0.117) or readmission rate (16.7% vs. 11.1%, P=0.632) between the groups. Conclusions: A fat-controlled diet and medication without fasting provided adequate initial treatment for chylous ascites after radical gastrectomy for gastric cancer.ope

Changes in failure to rescue after gastrectomy at a large-volume center with a 16-year experience in Korea

Failure to rescue (FTR), the mortality rate among patients with complications, is gaining attention as a hospital quality indicator. However, comprehensive investigation into FTR has rarely been conducted after radical gastrectomy for gastric cancer patients. This study aimed to assess FTR after radical gastrectomy and investigate the associations between FTR and clinicopathologic factors, operative features, and complication types. From 2006 to 2021, 16,851 gastric cancer patients who underwent gastrectomy were retrospectively analyzed. The incidence and risk factors were analyzed for complications, mortality, and FTR. Seventy-six patients had postoperative mortality among 15,984 patients after exclusion. The overall morbidity rate was 10.49% (1676/15,984 = 10.49%), and the FTR rate was 4.53% (76/1676). Risk factor analysis revealed that older age (reference: < 60; vs. 60–79, adjusted odds ratio [OR] 2.07, 95% confidence interval [CI] 1.13–3.79, P = 0.019; vs. ≥ 80, OR 3.74, 95% CI 1.57–8.91, P = 0.003), high ASA score (vs. 1 or 2, OR 2.79, 95% CI 1.59–4.91, P < 0.001), and serosa exposure in pathologic T stage (vs. T1, OR 2.74, 95% CI 1.51–4.97, P < 0.001) were associated with FTR. Moreover, patients who underwent gastrectomy during 2016–2021 were less likely to die when complications occurred than patients who received the surgery in 2006–2010 (OR 0.35, 95% CI 0.18–0.68, P = 0.002). This investigation of FTR after gastrectomy demonstrated that the risk factors for FTR were old age, high ASA score, serosa exposure, and operation period. FTR varied according to the complication types and the period, even in the same institution. © 2023, The Author(s).ope

Determination of Additional Surgery after Non-Curative Endoscopic Submucosal Dissection in Patients with Early Gastric Cancer: A Practically Modified Application of the eCura System

Background: Additional surgery after non-curative endoscopic submucosal dissection (ESD) may be excessive as few patients have lymph node metastasis (LNM). It is necessary to develop a risk stratification system for LNM after non-curative ESD, such as the eCura system, which was introduced in the Japanese gastric cancer treatment guidelines. However, the eCura system requires venous and lymphatic invasion to be separately assessed, which is difficult to distinguish without special immunostaining. In this study, we practically modified the eCura system by classifying lymphatic and venous invasion as lymphovascular invasion (LVI). Method: We retrospectively reviewed 543 gastric cancer patients who underwent radical gastrectomy after non-curative ESD between 2006 and 2019. LNM was evaluated according to LVI as well as size >30 mm, submucosal invasion ≥500 µm, and vertical margin involvement, which were used in the eCura system. Results: LNM was present in 8.1% of patients; 3.6%, 2.3%, 7.4%, 18.3%, and 61.5% of patients with no, one, two, three, and four risk factors had LNM, respectively. The LNM rate in the patients with no risk factors (3.6%) was not significantly different from that in patients with one risk factor (2.3%, p = 0.523). Among patients with two risk factors, the LNM rate without LVI was significantly lower than with LVI (2.4% vs. 10.7%, p = 0.027). Among patients with three risk factors, the LNM rate without LVI was lower than with LVI (0% vs. 20.8%, p = 0.195), although not statistically significantly. Based on LNM rates according to risk factors, patients with LVI and other factors were assigned to the high-risk group (LNM, 17.4%) while other patients as a low-risk group (LNM, 2.4%). Conclusions: Modifying the eCura system by classifying lymphatic and venous invasion as LVI successfully stratified LNM risk after non-curative ESD. Moreover, the high-risk group can be simply identified based on LVI and the presence of other risk factors.ope

Short-term outcomes and cost-effectiveness of laparoscopic gastrectomy with articulating instruments for gastric cancer compared with the robotic approach

To overcome the limitations of laparoscopic surgery, robotic systems have been commonly used in the era of minimally invasive surgery despite their high cost. However, the articulation of instruments can be achieved without a robotic system at lower cost using articulating laparoscopic instruments (ALIs). Between May 2021 and May 2022, perioperative outcomes following laparoscopic gastrectomy using ALIs versus robotic gastrectomy were compared. A total of 88 patients underwent laparoscopic gastrectomy using ALIs, while 96 underwent robotic gastrectomy. Baseline characteristics were similar between the groups except for a higher proportion of patients with a medical history in the ALI group (p = 0.013). Clinicopathologic and perioperative outcomes were not significantly different between the groups. However, the operation time was significantly shorter in the ALI group (p = 0.026). No deaths occurred in either group. In conclusion, laparoscopic gastrectomy using ALIs was associated with comparable perioperative surgical outcomes and a shorter operation time compared to robotic gastrectomy in this prospective cohort study. © 2023, The Author(s).ope