마이크로 컴퓨터를 利用한 淺海底 高解像 反射法 彈性波 探査資料의 取得 및 處理에 關한 硏究

이호영 서울대학교 대학원 1991 국내박사

사회인야구 참여자의 여가만족도와 자아존중감의 상관관계 분석

이호영 인하대학교 교육대학원 2021 국내석사

본 연구는 사회인야구 참여자들의 일반 특징인 결혼 여부, 연령대, 선수 경험, 참여 목적, 참여 횟수, 참여 기간 등의 정도에 따른 여가만족도와 자아존중감 사이의 차이와 상관관계를 규명하여 바람직한 여가활동으로써 사회인야구 참여의 필요성을 확인하는 것에 목적이 있다. 설문조사 내용에서 여가만족도는 사회적, 정서적, 신체적인 만족도의 세 가지의 하위요인으로 구분하였고, 자아존중감도 정서적, 신체적 자아존중감의 두 가지의 하위요인으로 구분하였다. 본 연구의 대상은 2020년 인천광역시 사회인 야구팀에서 선수로 참여하고 있는 참여자에 한 해, 온라인 설문 방식으로 조사를 진행하였다. 이러한 연구 과정을 통해 얻은 결과를 종합하면 다음과 같다. 첫째, 연구대상의 특징에 따른 여가만족도와 자아존중감의 차이를 살펴보면, 참여 목적과 참여 기간과 같은 항목에서 유의미한 차이가 나타났다. 그러나 결혼 여부, 연령대, 선수 경험, 참여 횟수와 같은 다른 항목에서는 여가만족도와 자아존중감 사이에 유의미한 차이가 나타나지 않았다. 둘째, 사회인야구 참여자의 여가만족도와 자아존중감 사이의 상관관계를 살펴보면, 사회인야구 참여로 인한 사회적, 정서적, 신체적 여가만족도는 참여자의 정서적, 신체적 자아존중감의 하위 항목별로 전부 또는 일부의 정적 관계가 있음이 밝혀졌다.

절연유에서의 방전과 전기유체역학의 다중물리 해석

이호영 경북대학교 대학원 2014 국내박사

The electrohydrodynamics (EHD) technique is used widely for electromagnetic systems from the nano- to macro-scale, such as nano jets, patterning, EHD cooling, electrocoalescence, electric curtain, etc. In electromagnetic systems, such as CPUs, switching components, inductors, transformers, etc., thermal management is a critical issue in a design or a proper operation. When a dielectric liquid is used as a coolant, EHD pumping techniques can be used to enhance the cooling performance. A fully coupled Finite Element Analysis (FEA) technique is developed and tested to validate the cooling effects of a dielectric liquid stressed by an electric field, resulting in the ionic dissociation phenomenon. Recently, electrohydrodynamics techniques have been applied widely to enhance the cooling performance of electromagnetic systems by introducing gaseous or liquid media. The main advantage of an EHD cooling is non-contact and a low-noise resulting from smart control using an electric field. In addition, in some cases, the flow can be achieved using only a main electric field source not an extra one. The driving sources in an EHD flow are an ionization in the breakdown region and ionic dissociation in the sub-breakdown region. Without an electric breakdown in systems to avoid an electric shock, the conduction pumping technique has been proposed and studied widely through the experiments. In this conduction pumping technique, ionic dissociation plays a key role driving fluidic flow. This physical setup can be resolved using the Poisson, Nernst-Planck and Navier-Stokes equations. To analyze this flow precisely, the discharge mechanism should be understood well including molecular dissociation and recombination incorporated with fluidic dynamics. Until now, these studies have focused on experimental work with few performing systematic numerical studies. In addition, no study has examined the cooling effects with the temperature distribution. Recently, a discharge simulation setup was developed in gaseous or dielectric liquids. In particular, some studies including the authors’ study focused on a liquid dielectric medium, and developed a reliable simulation setup on streamer propagation with three carrier governing equations due to the step or lightning voltage input. In this study, the Navier-Stokes equation and energy balance equation for the temperature field in a test body were added to analyze the cooling effect driven by the EHD phenomena. This might be the first approach to show the validity of the cooling effects with a reliable discharge simulation setup. From the proposed numerical technique, the temperature was decreased dramatically compared to that without a fluidic flow effect. This study focused on dielectric liquid flow driven by the ionic dissociation phenomena, resulting in a cooling effect of the heat source. To build on this EHD phenomenon, fully coupled FEA, which consisted of the Poisson’s equation for an electric field, Nernst-Planck equations for ions, and the Navier-Stokes equation for incompressible fluidic flow, was performed. To confirm the cooling effects, the developed velocities of fluidic flow were tested with the different applied voltages. In the sub-breakdown region, the effective velocity was approximately 2 m/s in the tip-sphere electrodes and a temperature drop of approximately 40 °C was obtained in a numerical analysis model with a fluidic velocity of 1.96 m/s from the inlet.

다중물리 해석기법에 의한 절연유체 내 공간전하 전파 유한요소 해석

이호영 경북대학교 대학원 2011 국내석사

The response of lightning impulse voltage was explored in dielectric liquids employing the hydrodynamic modeling ith three charge carriers by using the finite element method. To understand the physical behaviors of discharge phenomena in dielectric liquids, the response of step voltage has been extensively studied recently by using numerical techniques. That of lightning impulse voltage, however, was rarely seen in technical literatures. We, therefore, tested the impulse response with a tip-sphere electrode which is explained in the IEC standard #60897 in detail. Because the electric field dependent molecular ionization is a dominant term for breakdown process, two ionization factors were tested and compared for selecting a suitable coefficient with the lightning impulse voltage. To stabilize our numerical setup, the artificial diffusion technique was adopted and the finer mesh distribution was generated along with the axial axis. We found that the velocity from the numerical result corresponded to that from the experimental result of lightning impulse breakdown testing in the literature. Dielectric liquids are widely used for many electrical insulation technologies such as transformer oil. When compared to gaseous or solid insulation, dielectric liquids generally offer greater electrical insulating strength, superior thermal conductivity, higher performance, and greater ease of use. One of the key issues for insulating liquids is to predict the electrical breakdown which is the final stage in the electrical breakdown process including several pre-breakdown stages. This breakdown is basically based on the charge injection and transport phenomena between electrode and dielectric liquid. To analyze these mechanisms, charge continuity equations and Poisson’s equation for the electric scalar potential must be self-consistently satisfied. The distributions of space charge in a streamer propagating channel might have a shock-wave pattern, which causes severe numerical instabilities, due to the abrupt injection and propagation of space charge. This belongs to the convection-diffusion problems formed by the strongly dominant convection in the charge continuity equation. To decrease the numerical instability at the front of streamer head, here, the artificial diffusion technique was adopted. Even though the dimensional governing equations were explained, here, we used the non-dimensional governing equations with the non-dimensional variables expressed in the literature. By this non-dimensional approach, the numerical stability could be enhanced and more stable because the quantities in non-dimensional regime were much smaller than those in dimensional one. The lightning impulse response is one of important characteristics in power apparatus to represent the breakdown strength. In addition, engineers want to predict the breakdown strength and to have the breakdown information during the streamer propagation for designing the power systems. For these reasons, here, the numerical setup was tested for suggesting a suitable coefficient. Especially, the ionization coefficients, viewed in the literature for the step voltage response, were tested with the lightning impulse response. Eventually, we found that the velocity from the numerical result corresponded to that from the experimental result of lightning impulse breakdown testing in the literature. Like many other numerical and experimental works, we also adopted the tip-sphere electrode model suggested by the IEC standard #60897 model stressed by the applied voltage 300 kV.

초음파 4D 트랜스듀서의 구동조건 최적화에 관한 연구

이호영 경북대학교 대학원 2010 국내석사

In this study, it was represented of the method to find the best driving condition for the ultrasonic 4D transducer making the real-time medical image, which actually applied the method to the ultrasonic 4D transducer. The driving parts which makes an 1D array rotated are composed of the wobbling mechanism, step motor, and motor controller. The driving conditions are comprise of the motion profile, wobbling rate, wobble angle, section of acceleration & deceleration and input current value. Based on these conditions, performance values of the ultrasonic 4D transducer, that are the tracking error, hand arm vibration level, sound noise level, temperatures rise of cap surface, temperatures rise of step motor surface, had been measured and analyzed. Through estimating the driving performance of the ultrasonic 4D transducer in accordance with the driving condition of the motor controller which controls the wobbling motion of 1D array, it was investigated of the technique to find out the driving condition exhibiting the optimum performance of the ultrasonic 4D transducer.

Half-titanocene에 의한 스티렌과 스티릴-POSS의 공중합

이호영 경북대학교 대학원 2007 국내석사

The metallocene-methylaluminoxane (MMAO) catalyst systems had been found to give high catalytic activity for olefin polymerization and metallocene catalysts technology was successfully employed in polyolefin industry. Recently, a great deal of attention has been focused on nanocomposite materials. In particular, the use of polyhedral oligomeric silsesquioxane (POSS) nanoparticles has been demonstrated to be an efficient method for designing hybrid nanocomposite materials. A typical POSS nanoparticle contains an inorganic Si_(8)O_(12) nanostructured skeleton surrounded by seven organic groups R(e.g., isobutyl, cyclopentyl, or cyclohexyl) on the corners to promote solubility with a host polymer matrix and unique group capable of undergoing polymerization. This has afforded the oppertunity to incorporate inorganic POSS cages into organic materials through copolymerizations. The copolymerizations of styrene and styryl-POSS were conducted by the half-titanocene such as CpTiCl₃, Cp*TiCl₃ with the modified methylaluminoxane cocatalyst. In the St/St-POSS copolymerization, for Cp*TiCl₃, the catalytic activity decreased with addition of St-POSS as comonomer. By the addition of comonomer, T_(m) of polymer became lower. But initial and maximum thermal decomposition temperature(T_(di)),(T_(dm)) became higher. and stereoregularity([rr]) are lowered compare with sPS. r₁ and r₂ of St(M₁) and St-POSS(M₂) were found to be 1.6 and 0.85, respectively. In the St/St-POSS copolymerization, for CpTiCl₃, the catalytic activity and thermal property were similar with copolymers prepared by Cp*TiCl₃. But, Steroregularity exhibited lower than Cp*TiCl₃. In the St/PMS/St-POSS terpolymerization with Cp*TiCl₃, the catalytic activity decreased in initial addition of St-POSS(1mol%), but it increased with addition of St-POSS(2mol%) as comonomer. Thermal property and stereoregularity exhibited lower than St/St-POSS copolymers. All of copolymers and terpolymers incorporated by St-POSS had bimodal or multi-modal peaks on GPC curve.

텍스처와 다밴드 데이터를 이용한 위성 영상 분류에 관한 연구

이호영 서강대학교 대학원 2003 국내석사

본 논문에서는 흑백 단영상의 텍스처 정보와 다밴드 영상의 복사 에너지 정보를 이용하여 위성 영상을 분류하는 방법을 제안한다. 흑백 단영상에서 텍스처를 분석하여, 의미 있는 특징들로 구성된 영상들을 생성하기 위해 독립 요소 분석(ICA 방법2)를 사용하였으며, 또한 다밴드 영상의 복사 에너지 정보를 분석하여 이들을 독립 요소 영상(IC image)으로 분해하기 위해서도 독립 요소 분석(ICA 방법1)을 이용하였다. 생성된 영상들 중에서 클래스를 분류하는데 있어 높은 식별력을 가지는 영상만을 선택하여 특징 벡터를 구성하였으며, 특징 벡터를 분류하기 위한 방법으로는 감독 학습 알고리즘인 three-layered 신경 회로망을 이용하였다. 분류된 영상에서 랜덤하게 추출된 샘플들을 이용하여, 분류 성능을 정량적으로 분석하였으며, 4장의 실험 영상에 대해 제안한 방법은 대략 96%의 분류 정확도를 보인다. In this thesis, we propose a new classification algorithm to classify a remotely sensed image using texture of panchromatic image and radiometric values of multi-band images. ICA(Independent Component Analysis) is used to generate feature images by analyzing texture of panchromatic image. ICA is also used to separate IC(Independent Component) images from multi-band images by analyzing radiometric values. From generated images, images that have high discrimination power are selected and these selected images are used to organize feature vector. We use three layered neural network, one of supervised learning algorithm, to classify feature vector. Accuracy of classification is measured using samples that are randomly selected from classified image. We obtain the classification accuracy of approximately 96 percent in four experiment images.

一般系 高等學校 學生 奉仕活動 運營에 關한 敎師와 學生의 認識 比較

이호영 仁川大學校 敎育大學院 2003 국내석사

Purpose The purpose of this study was to compare a comparison between teachers' and students' perception about the student volunteering activities, intended to suggest some basic ideas for finding the desirable methods of student volunteering activities by comparing the students' and teachers' understanding about student volunteering activity and by analyzing the difference of those. In other to achieve the above purpose, the following problems were formulated. 1. What do the students think about the actual practice of student volunteering activity operated in academic high schools? Is there any difference by gender in their recognition? 2. What do the teachers think about the actual practice of student volunteering activity operated in academic high schools? Is there any difference by gender in their recognition? 3. Do the teachers and students have the different opinions about the student volunteering activity of the academic high school? Method This study is based on the questionnaires on the 480 high school students and 220 teachers randomly selected among 17 high schools in Bucheon, Kyongkido. The data was treated as follows: 1. Among returned questionnaires, if some given questions were not answered or if two more answers were chosen in multiple choice questions, that data was excluded. 2. The data was verified by the method of x(chi-squire). 3. The statistical significant level of verification is arranged "a=.05". Findings 1. The research shows that both boys and girls students have participated in volunteering activities a great deal. In case of boys students, the rate of participation is lower than that of girls students, on the others hand, they have spent much more time in volunteering than girls. It also shows that both are usually satisfied with the activities but their activities are not various, limited only to activities in public offices such as polic station or volunteering in their own school. 2. The students have the positive opinion about the system of student volunteering activities. Many students were confirmed as much time as they did actually in their volunteering confirmation note. It is proved that the problem of "intentional acting time extension in the confirmation note" is not really serious. Also, the majority of the students answered that when helping others they have no experience of receiving any items, foods and so on. It shows that there was no volunteering activity for the purpose of reward. 3. The teachers participating this research have the active and positive opinions about the student volunteering activities, However, there are not many teachers who considered the participation of volunteering as something helpful to study. Female teacher have much more negative opinions about the volunteering activities-the volunteering activities are rather harmful to study-than male teachers have. 4. In students' opinions participating in the volunteering activities with their "friends" is regarded as the most desirable. (37.8%) On the other hand, many teachers regarded the circle activity as the best. (40.0%) Many students think volunteering activity is helpful to school study but there are fewer teachers who agree with that. 5. The teachers and the students have much different opinions about the problem of the parents' interest in the volunteering activity. That is, the students think their parents are favorable to the activity and recommend the volunteering activity positively(46.9%), while the teachers think the parents dissuaded from volunteering(48%). The question of how they decide where to volunteer was given to the students participating the volunteering activity recently. Many student have got the idea from their teachers(43.3%), while the teachers from the teachers in charge of volunteering in the same school, from the local volunteering service center, or from the facilities.

자폐 검사 대조표에 의한 소아 자폐증에 관한 연구

李皓泳 忠南大學校 2000 국내석사

The study included 450 patients with behavior disorder, speech delay, developmental delay and mental retardation from January, 1990 to December, 1999. I analyzed these patients by Autism Behavior Cccklist I decided that total scores ≥68 indicated autism, 53-67 range indicated borderline, and scores <53 were normal. The results were as follows: l. Among the 450 patients, autism was 99(22%), borderline 117(26%), and normal 234(52%) by ABC. Male to female ratio was 3.5:1. The most common ages were 1-3 years old. 2. In order of frequency of associated disorders, 75 cases(75.6%) of mental retardation, 27 cases(27.3%) of attention deficit disorder, 25 cases(25.3%) of epilepsy, 16 cases(16.2%) of prematurity(16.7%), 10 cases(10.1%) of cerebral anomaly, etc. were observed. 3. The clinical manifestations of autism in order were delayed speech (87.9%), solitary play(76.8%). developmental delay(49.5%). hyperactivity (48.5%). cognitive dysfunction(35.4%). and seizure (27.3%), etc. 4. The abnormal laboratory findings were as follows; KWISC(75%), EEG(35.l%). brain MRI(12%), BAEP(8.9%). and chromosome(5.1%). 5. The total mean scores of autism, borderline and normal were 78.42, 59.01 and 27.76, respectively. The mean scores of Sensory, Relating, Body concept, Language, and Social Self Help on the subscales were 11.02, 17.74, 18.64, 16.14 and 15.98, respectively. The mean scores of 5 subscales were significantly high in autism(P<0.0l). Especially, the mean scores of Social Self Help subscale and that of Language subscale were higher in autism than non-autism. 6. There was no significant difference between delayed speech and speaking groups on the ABC total score. The speaking group showed significantly higher scores on the Language subscale, but delayed speech group showed significantly higher scores on the Sensory, Relating and Body concept subscales. I conclude that the early exact diagnosis of autism should be made by ABC and early treatment of autism improve prognosis.

혈중 Retinol Binding Protein 4(RBP 4)의 인슐린 저항성 및 아디포카인과의 관계

이호영 계명대학교 대학원 2011 국내석사

지방 조직은 단순히 잉여 에너지를 저장하는 조직이 아니라, 다양한 아디포카인을 분비하여 인체의 대사에 관여하는 중요한 내분비 조직으로 인식되고 있다. 비타민 A 수송 단백으로 알려져 왔던 RBP 4(retinol binding protein 4)는 최근 비만 및 인슐린 저항성과의 관계가 밝혀지면서 중요한 아디포카인의 하나로 연구되고 있다. Adiponectin 과 visfatin 도 지방에서 분비되는 아디포카인의 일종으로 당 및 지질대사에 관여하는 것으로 알려져 있다. 2002년부터 2003년 동산 의료원에서 검진을 시행한 환자 232명을 대상으로 대사성 인자 및 혈청 adiponectin, visfatin, RBP 4를 측정하였고, 이들의 상관관계를 분석하였다. 또한 인슐린 저항성을 알아보기 위해 HOMA-IR 을 계산하여 아디포카인과의 연관성을 알아보았다. 혈청 RBP 4는 혈압(r = 0.204, p = 0.002), 총 콜레스테롤(r = 0.235, p = 0.000), 중성 지방(r = 0.131, p = 0.048), 저밀도 지단백 콜레스테롤(r = 0.157, p = 0.018), 공복 인슐린(r = 0.161, p = 0.015), HOMA-IR(r = 0.159, p = 0.016), homocysteine(r = 0.248, p = 0.000), visfatin(r = 0.206, p = 0.002)과 통계적으로 유의한 양의 상관관계를 나타내었으나, 상관의 정도가 높지 않았다. RBP 4는 hsCRP(r = - 0.133, p = 0.045), adiponectin (r = - 0.153, p = 0.021)과 음의 상관 관계를 보였다. 또 adiponectin은 나이(r = 0.180, p = 0.006), 고밀도 지단백 콜레스테롤(r = 0.196, p = 0.003)과 양의 상관 관계를 보였다. 반면, adiponectin은 체질량 지수(r = - 0.252, p = 0.000), 공복 혈당(r = - 0.176, p = 0.007) 중성 지방(r = - 0.234, p = 0.000), 공복 인슐린(r = - 0.219, p = 0.001), HOMA-IR(r = - 0.198, p = 0.002)과 통계적으로 유의한 음의 상관관계를 나타내었다. Visfatin 은 RBP 4(r = 0.206, p = 0.002) 와 양의 상관 관계를 보이나 다른 대사성 인자와는 통계적 유의성을 보이지 않았다. 검진을 시행한 232명을 대상으로 혈중 아디포카인 및 대사성 인자들을 연구한 결과 RBP 4가 혈압, 혈중 지질 및 인슐린 저항성과 연관성을 보여 대사증후군에 주요한 아디포카인의 하나인 것을 확인할 수 있었으며, homocysteine 및 visfatin 과도 관련성이 있음을 확인할 수 있었다. 향후 RBP 4가 대사에 관여하는 정확한 기전과 더 많은 인구를 대상으로 한 전향적인 연구가 필요할 것으로 생각된다. Adipose tissue is traditionally considered energy storage deposit and metabolic sequelae of obesity, but now is regarded as active endocrine organ by producing adipokines to modulates homeostasis, blood pressure, lipid and glucose metabolism, inflammation and atherosclerosis. Retinol binding protein 4 (RBP 4) was recently shown to be linked to insulin resistance and obesity, and has attracted considerable attention as an important adipokine. Adiponectin and visfatin are also the kinds of adpiokines, involving to lipid and glucose metabolism. Plasma RBP 4, visfatin and adiponectin were measured in 232 healthy subjects who had undergone a medical examination in Keimyung University Dongsan Medical Center from 2002 to 2003 and then compared with various metabolic parameters. We studied the association of adipokine with insulin resistance and calculating HOMA-IR. RBP 4 levels were positively correlated with systolic blood pressure, total cholesterol, triglyceride, LDL-cholesterol, insulin, HOMA-IR, homocysteine and visfatin. And RBP 4 levels were negatively correlated with hsCRP and adiponectin. Adiponectin levels were positively correlated with age and HDL-cholesterol. But adiponectin levels were negatively correlated with BMI, fasting glucose level, triglyceride, insulin and HOMA-IR. Visfatin were positively correlated with RBP 4 but there was no statistical significance with other metabolic factors. These data suggested that RBP 4 levels were related to BP, serum lipid profile and insulin resistance, and RBP 4 was one of the adipokines which was important to the metabolic syndrome. These data also showed that RBP 4 was related to homocysteine and visfatin. Further studies are needed to analyze the precise machamism with RBP 4 and the accurate relation between RBP 4 and other adipokines. This study is retrospective and composed of small number, so further multicenter collaborations and large group trials are needed.