A Single-slope ADC with Digitally Programmable Dynamic Range for CMOS Image Sensor

Soo?Yang Park,Hee-Gyeong Yang,Sang?Hee Son,Won Sup Chung 대한전자공학회 2004 ITC-CSCC :International Technical Conference on Ci Vol.2004 No.7

Analysis of Insulation Diagnosis for Generator‑Motor Stator Winding in Pumped Storage Power Plant

Soo‑Hoh Lee,Tae‑Sik Kong,Hee‑Dong Kim 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

In this study, insulation diagnostic tests were conducted on pumped storage power plant (PSPP) generator-motor stator bars with artifcially simulated defects in order to improve solutions to perform preventive maintenance and track insulation diagnostic data for generator-motors by proving the efectiveness of insulation indices. Moreover, ozone (O3) concentration was estimated in order to relate it to partial discharge (PD) in laboratory to ensure the efectiveness of ozone as another index for insulation deterioration. By performing an ofine PD test and ultraviolet (UV) observation on one of the generator-motors during overhaul, and an ozone concentration measurement for the identical machine after the overhaul, it was concluded that ozone estimation could be a powerful index for insulation diagnosis under actual operational conditions. It was further developed that ozone measurement is useful to detect not only discharges in slots as mentioned in some studies but also discharges at the end-winding as proven in this study. The fndings of this study are expected to contribute to more reliable maintenance of generator-motors in PSPPs by achieving elaborate insulation diagnosis via multiple diagnostic indices.

Effect of Ultrasonic Melt Treatment on Solidification Microstructure of Al–5Ti–1B Alloy Containing Numerous Inoculant Particles

Soo‑Bae Kim,Jae‑Gil Jung,Young‑Hee Cho,Su‑Hyeon Kim,Kwangjun Euh,Jung‑Moo Lee 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

The effect of ultrasonic melt treatment (UST) on the solidification microstructure of an Al–5Ti–1B alloy containing highvolumefractions of Al3Tiand TiB2particles is investigated for various UST times with different melt holding times. Theas-cast Al–5Ti–1B alloy is composed of TiB2and polygonal Al3Tiparticles (present prior to UST), plate-like Al3Tiparticles,and Al grains (formed during UST and/or solidification). The UST causes a size reduction and homogeneous distributionof the TiB2-agglomerated region containing many submicron-sized TiB2particles pushed to the grain boundaries. The USTslightly decreases the size and improves the distribution of polygonal Al3Tiparticles enriched in the TiB2-agglomeratedregion. Unlike the TiB2and polygonal Al3Tiparticles, which exhibit a minor refining effect, the plate-like Al3Tiparticlesshow a significant refinement with UST application. The UST has a significant effect on the size distribution of Al grains byinducing the formation of medium-sized grains at the expense of small and large grains; however, it only has a slight effecton grain refinement. The degree of microstructure modification increases with increasing UST time but decreases with meltholding time after UST. The mechanisms for the refinement and dispersion of the TiB2and Al3Tiparticles and Al grains arediscussed considering fragmentation, nucleation, and growth behaviors induced by the UST and subsequent solidification.

Microstructure‑Strengthening Interrelationship of an Ultrasonically Treated Hypereutectic Al–Si (A390) Alloy

Soo‑Bae Kim,Young‑Hee Cho,Jae‑Gil Jung,Woon‑Ha Yoon,Young‑Kook Lee,Jung‑Moo Lee 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.6

Ultrasonic melt treatment (UST) was applied to an A390 hypereutectic Al–Si alloy in a temperature range of 750–800 °Cand its influence on the solidification structure and the consequent increase in strength was investigated. UST at such a hightemperature, which is about 100 °C above the liquidus temperature, had little effect on the grain refinement but enhanced thehomogeneity of the microstructure with the uniform distribution of constituent phases (e.g. primary Si, α-Al and intermetallics)significantly refined. With the microstructural homogeneity, quantitative analysis confirmed that UST was found tosuppress the formation of Cu-bearing phases, i.e., Q-Al5Cu2Mg8Si6, Al2Cuphases that form in the final stage of solidificationwhile notably increasing the average Cu contents in the matrix from 1.29 to 2.06 wt%. A tensile test exhibits an increasein the yield strength of the as-cast alloy from 185 to 208 MPa, which is mainly associated with the solute increment withinthe matrix. The important role of UST in the microstructure evolution during solidification is discussed and the mechanismcovering the microstructure-strengthening interrelationship of the ultrasonically treated A390 alloy is proposed.

압착방법별 포도 착즙액의 품질특성

최희돈,김성수,김경탁,홍희도,김상희 한국식품영양학회 2002 韓國食品營養學會誌 Vol.15 No.3

캠벨과 거봉을 이용하여 여러 가지 압착방법에 따른 착즙액의 이화학적 및 관능적 특성을 조사하였다. 수율의 경우 캠벨, 거봉이 동일하게 냉압처리보다는 온압처리가, 온압처리에서도 낮은 온도보다는 높은 온도에서 수율이 높게 나타났으며, 또 온압 · 펙틴분해 병행처리가 각각 83.5% , 87.3%로 가장 높은 수율을 나타내었다. 또한 당도와 아미노테 질소도 열처리온도의 상승 및 압착방법의 병행에 의해 감소하는 것으로 나타났다. 적정산도는 캠밸과 거봉이 압착방법에 따라 각각 0.86 ~ 1.00%, 0.60 ~ 0.69%로 거봉에 비해 캠벨의 산도가 높았으며, 열처리온도가 산도 증감에 더 큰 영향을 미치는 것으로 나타났다. 그리고 압착방법에 따른 착즙액에 대한 관능검사 결과 열처리 온도의 상승 및 착즙액에 대한 관능검사 결과 열처리온도의 상승 및 압착방법의 병행에 의해 떫은 맛과 산맛의 강도가 강하여지고 이들 처리구의 기호도가 높은 것으로 나타났다. The physicochemical and sensory properties of Campbell Early and Gerbong juices prepared by various pressing methods were studied. The yields of these juices by mixed method were 83.5% and 87.5%, the highest value of various pressing methods. And soluble solids and amino nitrogens of them decreased as heating temperature increased and was lowest when mixed method was performed. Titratable acidities of Campbell Early juice was 0.86 ~ 1.00%, higher than that of Gerbong juice, 0.60 ~ 0.69%. Also the strength of astringent taste and sour taste of Campbell Early and Gerbong juice increased as heating temperature increased, and increased strength of these tastes gave good sensory evaluation to grape juices.

인체구강상피세포의 배양조건에 대한 연구

박종수,최희웅,이수관,김수복,고광삼 中央醫學社 1990 中央醫學 Vol.55 No.2

Human epithelial cell cultures were initiated from explants of normal human oral mucosa. Growth parameter and cell type were assessed by DNA concentration and morphology of the cell lines. Tissues were excised and epithelial cells isolated by collagenase digestion. Spermine was used in order to inhibit overgrowth of the epithelial cells by fibroblast. The effects of different medium formulations were compared. Cultures maintained on the same volume of RPMI 1640 and Dulbecco's modified minimum essential medium containing 10 % fetal bovine serum, 10 ?g/ml of insulin, lng/ml of somatomedin and 10 ng/ml of epidermal growth factor showed optimal and maximal growth. For each cultured human oral epithelial cell the DNA content was in the- range of 5.7 pg to 6.6 pg. This culture system provides epithelial cells that can be used for a variety of dental and biochemical studies.

측뇌실내 수막종 : 임상분석 및 수술접근법 Clinical Analysis and Surgical Approach

양희진,김동규,정희원,이현구,김현집,조병규,최길수,한대희 대한신경외과학회 1992 Journal of Korean neurosurgical society Vol.21 No.10

The authors present six cases of lateral ventricle meningiomas treated at Seoul National University Hospital between 1979 and 1991. These six cases of lateral ventricular meningiomas constitute 1.8 percent of all intracranial meningiomas and 16.7 percent of mass lesions of the lateral ventricle. The mean age was 29 years ranging from 11 to 50 years, younger than that or intracranial meningiomas with a statistical significance(p<0.01). Four of the patients were women and two were men. All cases were located in the trigonal area. The most common clinical symptoms and signs were related to increased intracranial pressure such as headache, nausea and vomiting. Based on the clinical presentation and radiological features(CT. MRI and angiography), correct preoperative diagnosis was possible in five cases. Gross total removal of the tumor was achieved in all cases. There was no operative mortality. A temporal gyrus approach was used in five cases with good surgical results. The benefits and drawbacks of each surgical approach for meningiomas of the lateral ventricle is discussed with review of pertinent literatures.

경사 슬래브교의 지간/폭, 경사각에 따른 응력 상관성

남문희,정희효,이관희,이수경 慶尙大學校生産技術硏究所 1996 生産技術硏究所論文集 Vol.12 No.-

Skewed slab bridge have designed a width beam, stress of skewed slab bridge is quite different in according with skew and width /length. Especially in case that we analyse skewed slab bridge as a width beam, stress of right angle direction against axis of bridge is not analysed. In this study we will present the stress of transverse axis to longitudinal axis of bridge according to skew and width/length.

후두적출자의 의사소통 태도

강수균,박선희,백은아,이현혜,최경희,강은희,박은실 대구대학교 특수교육재활과학연구소 2005 특수교육재활과학연구 Vol.44 No.3

본 연구는 후두적출자의 주된 발성방법과 후두적출 경과 시기에 따른 의사소통 태도를 살펴보고자 하였다. 연구의 대상은 성인 남자 55명으로 후두암으로 인한 후두적출자들로 구성되었다. 이들에게 실시한 의사소통 태도 설문지는 Erickson의 의사소통 태도 척도-수정판(Modified Erickson Scale of Communication Attitudes: S-24)을 본 연구에 맞게 수정 보완하여 사용하였다. 본 연구의 결과는 첫째, 주된 발성방법에 따라서는 인공후두기 사용자와 식도발성자간의 의사소통 태도에 차이가 없었다. 둘째, 후두적출 경과 시기에 따라 10년 초과된 후두적출자들과 10년 이하의 후두 적출자들 간의 의사소통 태도에 차이가 없었다. 그러므로 이들의 의사소통 태도의 긍정적 태도를 증가시키기 위하여 다양한 방법을 활용하고 습득하여 이들의 의사소통 능력을 빠르게 재습득 하여 긍정적인 의사소통 능력을 가질 수 있도록 해야 한다. The purpose of this study was to determine laryngectomee's communication attitude. 55 laryngectomees, who were in the range of 40 years old to 80 years old participated in the study. Communication attitude measurements were taken by S-24(Modified Erickson Scale of Communication Attitudes). The results showed as follows: First, score of laryngectomees with artificial larynx and esophageal speakers were no significant. Second, score of laryngectomees with over 10 years after latyngectomy and 10 years after latyngectomy were no significant.

경연 대회를 통한 초ㆍ중고생의 창의력 신장 효과에 관한 연구

이희복,육근철,류해일,김현섭,김희수,박달원,유병환,김선효,김여상,서광수,변두원,서명석,배성효,박종석,심규철,이성희 공주대학교 과학교육연구소 2001 과학교육연구 Vol.32 No.1

미래 사회를 대비하기 위한 개인의 개성을 존중과 창의적인 능력을 지닌 인간을 양성을 목적으로 충청남도 지역의 초 ㆍ 중고등학생들을 대상으로 한 창의력 경연대회가 공주대학교 과학교육연구소에서 개최되었다. 충청남도 초 ㆍ중 ㆍ 고등학생들을 대상으로 실시한 창의력 경연대회는 창조적 아이디어를 내어 스스로 문제를 해결해 나갈 수 있는 교육 프로그램을 제공하는 좋은 기회였음이 확인되었으나, 일부의 팀에서만 참신하고 재미있는 아이디어들이 제안되었다. 여학생의 참가자 수가 상당히 증가하였으며, 대체적으로 입상권의 학생들의 상당 부분이 여학생이라는 것이 특이할만하다. 학년이 올라감에 따라서 창의적인 아이디어를 내는 양이나 질에 있어서 뒤떨어지는 것으로 분석되었으며, 토론 학습의 적응력이 미흡하고 발표력 및 청취력에 있어서도 떨어지는 것으로 나타났다. 따라서 중 ㆍ고등학교의 학교교육에서도 학생들에게 프로젝트형 탐구학습 프로그램의 적용은 물론 토론식 수습을 통한 학생들의 사고의 전환의 기회를 제공해야 할 것으로 사료된다. The creativity competition was held to foster the creativity of elementary and secondary school students in the Institute of Science Education, Kongju national University. It was found that the creativity competition effected on the improvement of inventing creative ideas and problem solving activities. But, only some competitors participated in semifinal and final contests, presented original and interesting ideas. More female students participated in competition than last year. More female participants were awarded a prize than males. Totally, participants were defective in discussion and communication, and presentation and listening ideas. Increasing grades correlated inversely with creativity and originality. There is need of inquiry project teaming programs and presenting opportunities of conversion of thinking by discussing instructions in school