[재료] PTA법에 의한 TiC 표면강화 알루미늉 Brake Disc의 제조 및 성능평가에 관한 연구

유승을(Seungeul Yoo),민준원(Joonwon Min) 한국자동차공학회 1999 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1999 No.11_2

Surface hardening of AC4C aluminium alloy brake disc with TiC powders was obtained by PTA(Plasma Transferred Arc) method. Machinability of the hardfaced area was tested with PCD (Poly Crystalline Diamond) and tungsten carbide tools. Dry, wet, and suction conditions were tested during machining. The flank wears of the tools were compared according to the machining conditions and the tool materials. The performance of TiC hard faced aluminium alloy brake disc was tested by brake dynamometer. The values of brake factor were in the range of 0.261-0.329, and the wear of brake disc was below 0.012 mm in thickness after dynamotest.

Assessment of the Evaluation of Liver T1 Mapping Imaging Applying Virtual ECG Gating on a Modified Look-Locker Inversion Recovery (MOLLI) Pulse Sequence

유승만,구은회,이석준,최보영 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.7

A T1 mapping calculation error may occur in a physicochemical environment with large relaxivity. We evaluated through a simulated electrocardiogram (ECG) the administration of a contrast withhigh relaxivity and its effect on the heart rate by using a modified Look-Locker inversion recovery(MOLLI) pulse sequence. The agarose 2% phantom of high relaxivity environment was developed bydiluting gadoxetic acid magnetic resonance imaging (MRI) T1 contrast media. The gold standardT1 determination was based on coronal single section imaging with a 2D inversion-recovery turbospin echo sequence (2D-IRTSE) in a 3T MR unit. Using the identical 3T MR scanner, we acquiredT1 mapping for the MOLLI pulse sequence with various virtual heart rates. T1 mapping dataof the two different pulse sequences (i.e., 2D-IRTSE and MOLLI) were measured to investigatethe accuracy and the specificity. An in vivo study was conducted in the same manner as thephantom experiments for liver T1 mapping imaging in three healthy volunteers. The MOLLI pulsesequence showed an error rate of less than 10% at a contrast agent concentration of 0.4 mmol/L,and significant error, compared with the reference value, was observed at 0.6 mmol/L or higher. The percentage error of the T1 value did not correlated with the RR (i.e., the time between heartbeats) change that was observed (P = .270). Based on the in-vivo liver test, T1 mapping imaging ofan abdominal organ as the liver can be successfully achieved using the applied virtual ECG gatingon the MOLLI sequence.

다함께 즐거운 방, 다락(多樂)방

유승아,김수빈,이동현,최예지 한국호텔외식관광경영학회 2015 한국호텔외식경영학회 학술발표논문집 Vol.- No.-

초등학교 4학년 학생들의 설명글과 이야기글 쓰기 양상 연구

유승아,이순영 고려대학교 한국어문교육연구소 2020 한국어문교육 Vol.32 No.-

This study collected 566 text samples written by 299 4th graders and analyzed their writing abilities focusing on quantity, quality, genders, and levels of writing. On average they produced 441 letters (expository) and 614 letters (story) in a text, and the number of sentences was 18.5 (expository) and 31.6 (story). These fourth graders showed an improvement in the length and accuracy in their writing compared to when they were lower graders. The pace of improvement, however, slowed significantly once they became fourth grade. From some characteristics of these fourth graders it could be said that they were entering a stage of ‘the text creation at the level of paragraphs and discourse.’ But their sentence structure was still simple, and the organization of writing was poor. In addition, both explanatory and story texts showed significant gender differences, and the gap between writing levels (especially between upper and lower groups) was also confirmed. The results of this study will contribute to the actualization of writing curriculum in elementary schools by providing empirical data on writing abilities of fourth grade students. 초등의 쓰기 교육은 표준적 글자 쓰기와 전사 능력의 습득을 강조하다가 점차 텍스트의 생성과 조직 능력을 증진하는 방향으로 진행된다. 초등학교 4학년은 문식성이 비약적으로 발달하고 교과 학습 내용이 고도화 되는 중요한 시기이다. 이에 이 연구에서는 299명의 초등학교 4학년생이 작성한 566편(설명글 282편, 이야기글 284편)의 글을 수집하여 학생들의 쓰기 능력을 분석하였다. 4학년생은 20분 동안 평균 441글자(설명글)와 614글자(이야기글) 분량의 글을 작성하였고, 문장 수는 18.5개(설명글)와 31.6개(이야기글)였다. 초등 저학년에 이어 단위 시간 동안 생성한 글의 분량(쓰기 유창성)은 매년 증가하였으나 4학년에 이르러 그 증가폭이 크게 둔화되었다. 4학년생은 전사 기능 확보와 같은 기초 쓰기 단계를 넘어서서 ‘문단·담화 수준의 텍스트 생성’ 단계에 진입한 특성을 보였다. 그러나 아직 문장의 구조가 단순하고, 글의 조직이나 사건 구성 능력이 미숙했다. 이외에도 설명글과 이야기글 모두 여학생의 성취가 남학생보다 높은 성차가 나타났으며, 쓰기 수준별(특히 상·하 집단의) 격차가 크게 벌어지는 특성도 확인되었다. 이 연구의 결과는 초등 고학년의 진입기이자 학습을 위한 문식성을 요구 받는 4학년 학생들의 실제 쓰기 능력에 대한 정보를 제공하여 학교의 쓰기 교육 교육과정을 실제화 하는 데 기여할 것이다.

『날개돋친 뱀』--남근주의의 정치학

유승 현대영미어문학회 2000 현대영미어문학 Vol.18 No.2

The novel is for Lawrence a kind of tool to represent his thought effectively. That's why he is called by some critics as a "prophetic novelist" or "thought adventurer." When we read, therefore, his novels, we must pay more attention to his idea than aesthetic form. What he truly seeks for is a real change of the diseased modern world and regeneration of mankind. It is The Plumed Serpent that dramatically reveals his most imaginative achievement: the novel's vivid portrayal of phallicism and its regenerative power. In this novel, Lawrence revives the myths of the pre-Aztec god Quetzalcoatl and establishes new society which is ruled by potent male leadership.

韓國 妊婦의 TORC H病原體에 關한 抗體 保有에 關한 硏究

柳承一,金善行,洪性鳳 고려대학교 의과대학 1985 고려대 의대 잡지 Vol.22 No.3

During the recent 15 years, there was a significant changes in the incidence of viral infection in pregnancy. In addition, TORCH agents are the most prevalent microbes among them, and their infections during pregnancy, either primary or recurrent, may affect the feauses in utero and the neonates at the time of delivery. Although we have achieved some progress in controlling them in the view point of prevention and treatment, but it is still insufficient. The purpose of this study is to determine the baseline prevalence of antibodies for TORCH agents during various stage of pregnancy in Seoul, Korea. From 92 asymptomatic pregnant women, 92 single serum sample were taken and examined the antibodies for TORCH agents by ELISA (C.M.V., R.V., H.S.V.) and H.A.I. test (Toxoplasmosis). The followings are the results. 1. The prevalences of antibodies to each of the TORCH agent were 1.08% for toxoplasma, 93.47% for C.M.V., 71.73% for R.V. and 84.74% for H.S.V. 2. The prevalences of antibodies for C.M.V. and R.V. were much higher in the term pregnancy group compared to early pregnancy. This findings suggest some evidence of vulnerability to viral infection during pregnacy. 3. The prevalences of C.M.V., R.V. and H.S.V. antibodies were in parallelism with the increasing age of women. Almost all women over 30-35 years had C.M,V., R.V., H.S.V. antibodies. 4. In multiparous women, the prevalences of antibodies for TORCH agents were higher than that in nulliparous women. 5. In the women with history of previous fetal wastage, the prevalence of TORCH antibodies were higher especially for C.M.V. compared with women without past history of previous fetal wastage.

디지털 시대와 문학 산업

유승 신영어영문학회 2001 신영어영문학 Vol.19 No.-

It has been said that art has reflected the industrial development and the masses' desire. As the digital technologies change our ways of life, so the literary industry including publication, literary contents and studies, if it wants to exist, must be changed. The debate over the "death of literature" begun in 1960s was the sign of the complex transformations of a literary paradigm in a time of radical political, technological, and social change. It is the mark of the new that we never know what it will be until it arrives. Of one thing we can be sure, that the masses will take the initiative in literary industry and the products of it will never be the outcome of existing trends. The digital age assigns meaning to such terms as e-book, inter-action, diversity, global standard, re-mapping, minority, hybridity and ecology. Though the traditional literary features will remain, the literary industry should reflect these ideas and upon which course of action to take.

뇌경색의 진단에서 확산강조 및 T2강조 영상의 유용성 비교

유승,양영모,유인술,김승환,하영록,정성필 대한응급의학회 2002 대한응급의학회지 Vol.13 No.2

Purpose: Diffusion-weighted magnetic resonance imaging (DWI) has been known to visualize hyperacute ischemic stroke. And it takes only a few minutes to do. Moreover only a small amount of time and little cost is required to add T2-weighted imaging(T2WI) to DWI. The purpose of this study is to determine the usefulness of T2WI in addition to DWI as a primary imaging modality for patients with suspected ischemic stroke. Methods: DWI plus T2WI was performed from January to May 2001 on the patients with suspected ischemic stroke. Two emergency physicians reviewed the films and medical records. The sensitivity and the specificity of DWI and T2WI for acute ischemic stroke were calculated. The agreement between DWI and T2WI was calculated using kappa statistics. Results: A total of 241 patients were enrolled. Acute ischemic stroke was confirmed in 86 (35.7%) patients. The sensitivity and the specificity of DWI for acute ischemic stroke were 94.2% and 98.7%, and those for T2WI were 60.5% and 94.2% respectively. The kappa value was 0.721 (p<0.01). Among the 86 acuted ischemic stroke patients, the number of cases who presented less than 6 hours after symptom onset was significantly lower in the T2WI positive group (31% vs. 68.7%, p<0.05). Conclusion: This study suggests that the addition of T2WI to DWI. as a primary imaging modality for acute ischemic stroke has little benefit compared to DWI alone, especially, when the symptom duration has been less than 6 hours.

꼽등이를 먹으면 꼽등이가 될까?

유승도 천년의시작 2023 (계간)시작 Vol.22 No.2

공중-지상 로봇 협동 기술과 그 응용 및 연구 방향

유승은(Seung-Eun Yu),김대은(DaeEun Kim) 제어로봇시스템학회 2010 제어·로봇·시스템학회 논문지 Vol.16 No.2

Researches on air-ground robot cooperating system has been made recently. The cooperation among homogeneous robots focused on the architecture of the system, quality and influence of the communication. In contrast, the cooperation among heterogeneous robots such as aerial vehicle and ground vehicle robots has not been much handled. There are a couple of main points for those air-ground cooperating robots. One is using UAV (Unmanned Aerial Vehicle) as an extra sensor of UGV (Unmanned Ground Vehicle). This kind of application is usually used in situations such as guiding UGV to an appropriate path which could be better determined from the eye in the sky as UAV. The other main application of air-ground cooperating robot system is the localization. By combining sensor information from both UAV and UGV, the robot system as a whole can localize a target object or find features in the environment with better performance than UGV or UAV alone. Although these applications are recently studied in many different ways and devices, there are still a lot of possibilities in the field of air-ground cooperating robot systems. We introduce those research fields in this paper.