수직원관 주위의 자연대류 응축열전달 실험

신종민 釜山大學校 1988 국내석사

Highly Improved Response and Recovery Characteristics of FET-type Gas Sensor using Pre-Bias

신종민 서울대학교 대학원 2018 국내박사

Recently, a gas sensor technology has become increasingly important due to the increasing demand for automobiles, air quality control, farming, and household appliances. Thus sensor technology is expected to play an important role in the Internet of Things (IoT) era. Various types of gas sensors such as optical, electrochemical, semiconducting and FET-based gas sensors have been widely reported so far. However, most of the studies on the gas sensors have been focused on resistor-type sensors and the investigation of sensing materials rather than the electrical control scheme. The resistor-type sensor has demerits in size, yield, and integration with CMOS circuits. Thus, to fulfill the demands for low cost, scalable, stable, and CMOS compatibility for the gas sensor, FET-type sensors have been widely studied. Although the FET-type sensors have a higher degree of freedom coming from four terminal features in enhancing the sensing performance, there have been no report on electrical control scheme. In this dissertation, we propose, for the first time, a pulse pre-bias scheme for enhancing the sensing performance of Si FET-type gas sensor and investigate the pre-bias effect on the response and recovery characteristics. The Si FET type gas sensor having a control-gate (CG) and a floating-gate (FG) in horizontal direction is fabricated to investigate the pre-bias effect. The ZnO film as a sensing material is deposited between the CG and the FG by ALD. By applying the pulse bias scheme to the CG of the FET-type gas sensor, the pre-bias effect is verified, and we analyze the reaction between NO2 gas and the ZnO as a sensing layer deposited on the Si FET-type gas sensor. The mechanism responsible for the pre-bias effect is explained using energy band diagram. The proposed scheme was verified to be very efficient in improving the gas response and the reduction of the recovery time to NO2 target gas. It is expected that the pre-biasing scheme will be very practical in the commercialization of the FET-type gas sensor.

재건축대상아파트의 환경친화적 개발을 위한 거주자 의식에 관한 연구

신종민 전북대학교 2002 국내석사

저에너지 전자빔을 이용한 연료전지용 백금 촉매 제조 기술 개발 및 전기화학적 특성 연구

신종민 忠南大學校 大學院 2021 국내석사

Recently, major countries such as Europe, the United States, and China trend to reduce carbon emission by increasing the use of renewable energy. Hydrogen energy is one of the most important renewable energy sources because it generates a higher energy density than solar power, wind power, and hydropower energy. This hydrogen energy can be used in a polymer electrolyte fuel cell (PEMFC) which can power electric vehicles or factories. A PEMFC stack for automobiles is composed of repeatedly stacking hundreds of membrane-electrode assemblies (MEAs), gas diffusion layers (GDLs), and separators. The most important component in determining the price, life, and performance of a fuel cell vehicle is MEA. Usually, MEA is manufactured by coating platinum (Pt) catalysts on both sides of an electrolyte membrane. The Pt catalysts cost about 50 % of the fuel cell stack price. In order to reduce the price of fuel cell vehicles and commercialize them, an innovative technique for Pt nanoparticles production is required. This study proposes the Electron Beam (EB) irradiation method to synthesize the Pt catalysts for PEMFC. This method uses a low-energy electron beam to irradiated the Pt solutions to produce Pt nanoparticles. In this technique, we can control the dispersion and size of Pt catalysts using dispersant and OH radical scavenger. By systematically controlling the amount of dispersant and radical scavenger, we found suitable conditions for synthesizing Pt nanoparticles for PEMFCs applications with small size particles and good dispersion. Thus, with this technique, the mass production of Pt catalysts can be achieved.

Fabrication of hollow manganese oxide nanoparticles for the MRI application and synthesis of Fe3O4/Pd and FePd nanoparticles through the solid-state reaction confined within a silica nanosphere

신종민 경희대학교 일반대학원 2010 국내석사

Hollow nanoparticles with interior void spaces are attractive candidates for advanced MRI contrast agents owing to their large water-accessible surface area, which is able to carry high payloads of MR-active magnetic centers, and the ability of the interior void space to take up large amounts of drug molecules. In this context, hollow manganese oxide nanoparticles were synthesized by selectively carving away the core from nanoparticle having MnO core coated by Mn3O4 shell. The hollow nanoparticles showed the greatly enhanced relaxivities and drug loading capacity, comparing with those having solid interior. Their efficient cellular uptake allowing for the delivery of anticancer reagents was also examined, demonstrating their potential as bifunctional medical system combining diagnostic imaging and drug treatment. Due to their potential to integrate different functionalities in individual nanocrystals, the hybrid nanocrystals have been receiving significant current attention. In this work, we synthesized anisotropically phase-segregated Fe3O4/PdO heterodimers nanocrystals during the thermal annealing of silica nanospheres encapsulating Fe3O4 nanocrystals and Pd2+ complexes. When the nanospheres containing the heterodimer were annealed under reductive environment, it was revealed that the nanostructure were converted into either Fe3O4/Pd heterodimers or FePd alloy nanocrystals depending on the annealing temperature. In this presentation, we will report the synthesis and controllable transformation of Fe3O4/PdO heterodimer in silica nanosphere.

주전산기 CPU 사용량 감소를 위한 개선대상 프로그램 선정 모델에 관한 연구

신종민 고려대학교 컴퓨터정보통신대학원 2008 국내석사

부하를 분산 하여 시스템 자원의 효율성을 제고하여 시스템의 안정성을 향상하고자 하는 연구는 부하분산 에이전트 이용, 네트워크 트래픽의 동적 감시를 통한 부한 분산, 클러스트 환경을 이용한 부하분산, Queue를 통한 트랜잭션을 제어에 의한 부하 분산 등이 있다. 또한 어플리케이션 부문은 프로그램 로직 단순화 및 SQL 최적화 등을 실시하여 부하를 경감하는 연구가 진행 되고 있다. 그러나 어플리케이션 부문의 튜닝을 실시하기 위한 대상 프로그램의 선정 및 튜닝 실시 후 사후 관리 방법에 대한 연구는 활발히 이루어 지지 않았다. 따라서 본 논문은 시스템 부하 개선을 위한 튜닝 대상 프로그램 선정 모델을 제시하고, 이를 실 업무에 적용하여 본 연구 모델의 실용성을 검증 하였다

十二指腸潰瘍과 胃線癌 患者에서 Helicobacter pylori 毒性因子 遺傳子 阿兄과 IS605의 役割

辛鍾珉 동아대학교 2001 국내박사

목적: Helicobacter pylori(H. pylori)의 cagA, vacA 및 iceA 유전자는 주요 독성인자로 알려져 있으며 십이지장궤양과 위선암 발생에 관여하며, IS605도 cag pathogenicity island(PAI)의 재배열과 결손을 만들어 cag PAI의 독성을 변하게 한다고 알려져 있다. 하지만, 이들 독성인자와 임상질환의 연관성에 대한 결과는 지역에 따라 다르다. 본 연구에서는 cagA, vacA, iceA의 유전자형과 아형 및 IS605를 조사하고 위선암 및 십이지장 궤양과의 연관성을 밝히고자 하였다. 대상 및 방법: ureC 유전자와 16S rRNA을 이용하여 H. pylori 감염 양성으로 확인된 81명(십이지장궤양 27명, 위선암 24명, 대조군 30명)을 대상으로 하였다. PCR을 이용하여 cagA, vacA 및 iceA의 유전자형을 조사하고, 또한 IS605에 대해서도 조사를 하였다. 결과: H. pylori 양성률은 대조군(48.5%)에 비해 십이지장궤양군(81.6%, p<0.001)과 위선암군(77.8%, p=0.004)에서 높았다. cagA 양성인 경우는 대조군(66.7%)에 비해 십이지장궤양군(88.9%, p=0.046)에서 많았으며 cagA 음성인 경우는 대조군(33.3%)에 비해 위선암군(62.5%, p=0.033)에서 많았다. vacA와 iceA의 아형과 질환과의 연관성은 없었다. cagA, vacA 및 iceA 유전자형을 조합한 결과 중에는 cagA^+ vacA s1-m1 iceA1이 가장 흔한 아형이었다. cag PAI내 IS605는 십이지장궤양군, 위선암군 및 대조군에서 발견되지 않았고, 전체 게놈 중 IS605의 발현률은 십이지장궤양군에서 59.3%, 위선암군에서 33.3%, 대조군에서 36.7%로 각 군간에 차이는 없었다. 하지만 cagA와 IS605에 따른 임상질환과의 연관성을 보면 십이지장궤양군에서 cagA^+/IS605^+ 경우가 대조군에 비해 약 2배정도 많았으며(51.9% vs. 26.7%), cagA^-/IS605^- 경우가 가장 적었다(3.7% vs. 23.3%, p=0.033). 위선암군에서는 cagA^+/IS605^- 경우가 대조군에 비해 가장 적었으며(12.5% vs. 40.0%, p=0.025), cagA^-/IS605^- 경우가 가장 많았다(54.2% vs. 23.3%, p=0.02). 십이지장궤양군에서는 IS605 유무에 관계없이 cagA 양성에 따라 궤양의 발생이 많았다. 결론: H. pylori 양성인 경우에 십이지장궤양과 위선암의 발생이 많았으며 특히 cagA^+/IS605^+/-은 십이지장궤양과 연관성이 있었으며 cagA^-/IS605^-은 위선암과 연관성이 많았다. vacA와 iceA는 십이지장궤양 및 위선암과의 연관성이 없었다. Background/Aims: The H. pylori cagA gene, vacA gene and iceA gene are considered to be important virurence factors that have been implicated in the development of duodenal ulcer and gastric adenocarcinoma. It was reported that the presence of IS605 elements may be responsible for rearrangements and lead to partial or total deletions of the cag pathogenicity island (PAI) and the virulence of cag PAI may be changed. However, different results regarding the association between these virulence factors and clinical disease have been reported from different geographic regions. This study evaluated the relationship between H. pylori virulence factors such as cagA, vacA, iceA, IS605 and duodenal ulcer and gastric adenocarcinoma. Methods: H. pylori isolates were obtained from 81 infected patients ( 27 cases of duodenal ulcer, 24 cases of gastric adenocarcinoma, 30 cases of control). H. pylori isolates were identified by PCR with ureC gene and 16S rRNA. PCR was performed to examine cagA, vacA, iceA and IS605 genotypes. Results: The positive rates of H. pylori in duodenal ulcer group (81.6%, p<0.001) and gastric adenocarcinoma group (77.8%, p=0.004) were significantly different from control (48.5%). The positive rate of cagA in duodenal ulcer group (88.9%, p=0.046) was also significantly different from control (66.7%). Significant difference was found in the negative rates of cagA between gastric adenocarcinoma group and control (62.5% vs. 33.3% p=0.033). No significant difference was found in the prevalence of iceA, vacA among these group. The genotype of cagA^+ vacA s1-m1 iceA1 was predominant in H. pylori isolates irrespective of the clinical outcome. IS605 in PAI was not found in duodenal ulcer group, gastric adenocarcinoma gruop and control. The positive rates of IS605 in genome were 59.3% in duodenal ulcer group, 33.3% in gastric adenocarcinoma group and 36.7% in control (p>0.05). In duodenal ulcer group, the positive rate of cagA^+/IS605^+ was about two times as many as in control (51.9% vs. 26.7%) and the positive rate of cagA^-/IS605^- was lower than in control (3.7% vs. 23.3%, p=0.033). In gastric adenocarcinoma, the positive rate of cagA^+/IS605^- was lower than in control (12.5% vs. 40.0%, p=0.025) and the positive rate of cagA^-/IS605^- was higher than in control (54.2% vs. 23.3%, p=0.02). The presence of IS605, whether in cagA^+ or cagA^- strains of H. pylori, did not systematically modify the severity of duodenal ulcer. Conclusions: We could confirm the relationship between cagA^+ and duodenal ulcer and between cagA^-/IS605^- and gastric adenocarcinoma. However, other virulence factors had not related significantly with gastric adenocarcinoma and duodenal ulcer. Further study is needed to examine the specificity of H. pylori strains.

동적 평면 제어기법을 이용한 탄-소성 마찰모델 기반의 비선형 서보시스템 정밀위치제어

신종민 부산대학교 2012 국내박사

This paper presents precise position control method of nonlinear servo system with nonlinear friction and uncertainty and the performance of proposed position control system was evaluated from simulation and experiment. One of the problem to overcome to implement high precision servo control is friction which exists between the contact surfaces of two materials. Friction phenomenon has been studied by many researchers and many friction model in order to capture the unique friction properties have been improved or developed. LuGre friction model is representative friction model and many friction compensation schemes based on LuGre friction have been presented in order to alleviate the tracking performance. However, LuGre has shortcoming that do not exactly presents stiction and pre-sliding displacement which happen in pre-sliding region. Elasto-plastic friction model was developed in order to overcome this problem. Elasto-plastic model displays friction phenomenon by dividing to elastic deformation section and plastic deformation section. In the Elasto-plastic model, interior state variable and pre-sliding displacement are important design parameters which decide friction properties. In order to implement friction compensation scheme based on mathematical friction model, identification of parameters for friction model is required. Identification of friction parameters is very difficult to require much times and effort. In addition, even with successful completion of the friction identification process, it is difficult to achieve desirable tracking performance due to time-varying characteristics of the nonlinear friction which depend on precision manufacturing, lubrication, temperature, and contamination. Therefore, friction parameter observation technique is needed to apply friction model in precision position control system. Although precision control schemes are very effective for compensating nonlinear friction, the performance of position control system can be limited by system uncertainty which is occurred by some assumption or neglected disturbance in modeling process. To deal with unknown system uncertainties effectively, artificial intelligent(AI) schemes such as fuzzy and neural networks algorithms can be used to compensate system uncertainties. AI schemes can effectively approximate any continuous function. Application of estimation methods for nonlinear friction and system uncertainties should be achieved carefully. Over-estimation for unknown parameters or uncertainties can influence in stability of position control system. Therefore, dynamic surface control method is adopt to consider over estimation problem of friction observer and system uncertainty estimator at position controller design process. Traditional back-stepping algorithms, although systematic, suffer from an ‘explosion of complexity’ due to the necessity to perform repeated differentiations of the nonlinear functions. Because dynamic surface control scheme uses first-order filtering of the synthetic inputs at each level of the traditional back-stepping approach, organization of control input is simple than control input of back-stepping control scheme. In order to evaluate proposed position control system, simulation and experiment carry out for scorbot robot system and ball-screw system.

아웃소싱 데이터베이스를 위한 효율적인 집계 질의 인증 기법

신종민 서울대학교 대학원 2017 국내석사

데이터베이스 아웃소싱은 기업 및 기관에서 빅데이터 분석을 위해 사용하는 보편적인 방법으로 자리잡고 있다. 데이터 소유자는 데이터베이스 아웃소싱을 통해 질의 처리와 같은 계산량이 많은 작업과 저장 및 관리 등의 업무를 제 3자 서버에 위탁할 수 있다. 이러한 패러다임은 데이터 소유자가 비싼 인프라를 구축하지 않고도 대용량의 데이터를 관리할 수 있게 한다. 하지만 보안상 위협이 항상 존재하는 네트워크의 특성상 제 3자 서버는 데이터를 변조하고 질의 결과를 조작하는 공격자들의 공격에 노출되어있다. 따라서 서버는 사용자에게 질의 결과가 정확하다고 증명할 수 있어야 한다. 이러한 문제를 해결하기 위해 구간 질의, kNN 질의, 함수 질의 등 다양한 질의에 대한 인증 기법들이 연구되었다. 하지만 빅데이터 분석에 있어 집계 질의의 활용도가 높음에도 불구하고 집계 질의에 대한 인증 기법 연구는 부족하며 기존 연구는 고차원 데이터나 서로 다른 값의 수가 많은 데이터에 대해 비효율적이다. 본 연구에서는 집계 질의 인증을 위한 자료구조 AMR–tree를 제안한다. 그리고 독립 노드와 독립 서브트리 개념을 도입하고 AMR–tree를 활용한 효율적인 증거 생성 방법과 증명 방법을 제안한다. 그 후 제안한 기법의 성능을 검증하기 위해 데이터의 상이 값 수, 레코드 개수, 그리고 차원 크기를 각각 변경시켜가며 실험을 진행하였으며 실험 결과를 통해 제안한 기법의 성능이 우수함을 보였다.

차량의 자율 주행을 위한 다변수 슬라이딩 모드 제어

신종민 부산대학교 대학원 2004 국내석사

The autonomous vehicle control system is presented in this paper. The nonlinear vehicle model with the coupled inputs is considered. In our research, using nonlinear transformation for decoupled input. And in order to design of control system, the sliding mode control system is used. Sliding mode control system leads to chattering. To reduce chattering, the modified sliding mode control law is proposed. Proposed control law involve system error state in signum term. Simulation results show that the proposed approach is effective to reduce chattering.