딥러닝 기반 컴퓨터 비전의 공정성을 위한 기법 조사 - 학습 데이터를 중심으로

김대혁(Dae-Hyeok Kim),유창동(Chang-Dong Yoo) 대한전자공학회 2022 대한전자공학회 학술대회 Vol.2022 No.6

대학수학능력시험 도입후의 고교교육 변화에 관한 연구

박병량,변영계,한대동,성병창 교육연구소 1994 敎育硏究 Vol.4 No.1

Under the current school system in which secondary schools aim at the preparation for college entrance, the college entrance examination has a crucial impact on high school education. The former college entrance examination has been accused of causing many problems in high school education such as training students, in a recital mode, by giving fragmentary knowledges and skills picked up by teachers largely for the college entrance emanination. Under the examination system students were not recommended either in school or at home to pursue their own interests and concerns which are supposed to enhance higher order thinking including creativity. In order to reform this change-resisting high school education a new type of college entrance examination called College Scholastic Aptitude Test (CSAT, hereafter) replaced the former one in 1990 in the worldwide tide of educational reform toward the quality education. This study is to examine whether and/or to what extent the newly introduced CSAT has brougght changes to high school education. This study began with two concrete research problems. First, to what degree did the CSAT affect high school students particularly in the areas of attitudes toward school, classroom learning and instruction, and study habits? This refers to personal effects separated from school education. Second, to what extent did the CSAT make changes in high school education? This refers to institutional effects. As a survey, this study collected questionnaire data from 1,600 male and female high school third graders from 33 high schools locatedin Pusan City and its surrounding KyungNam-Do province. The CSAT was firstly introduced in 1990 when the survey respondents were then high school freshmen. The sample method is a systematic cluster random sample. After schools had been randomly selected about 60 students(2 classes) were sampled from each school. The questionnaire consisted of questions asking largely whether any changes were made in the areas such as individual student's studying strategies and their perceptions of schooling. The students' responses were analyzed according to concrete research problems using appropriate statistical methods. The research results are summarized as follows. First, according to students' responses they evaluated that CSAT was somewhat successful in measuring higher order thinking and somewhat conducive to lessening social problems cuased by excessively competitive high-cost private lessons. The new exam, however, unexpectedly did not have affirmative effects on such areas as: undesirable operation of high school; measurement of learning ability; selection of college qualifiers; and test item difficulty and discrimination. Second, the effects of CSAT on school-based tests were found to be both slightly positive and negative. For the positive side of the effects, the test content was not confined to textbooks but taken either from other non-text sources or from what was taught in classrooms beside textbooks; in solving the test questions not only correct answers were not required but also the problem-solving processess were also emphasized in schools. In following areas, however, there were almost no changes made: the dominance of multiple-choice test items; anxiety of testers; the utilization of test results for own learning improvement; and the frequent school testing. Third, since the introduction of CSAT there have been almost no improvements in school organizational practices, management, and climates such as; extracurricular activities, communications with teachers, guidance and discipline, teachers' expectations of students, grouping of students according to ability and talent, and friendship among classmates. One exception was that classroom climate has become somewhat open and democratic than before. Fourth, with regard to classroom activities some improvements have been detected. The classroom instruction has been somewhat changed into one emphasizing higher order thinking. It was revealed through teachers' efforts to employ new teaching methods and to carry out curriculum in a regular basis, to try to upgrade expectations of students, and to make classroom learning more explorative. On the other hand, in other areas of classroom activities it was hard to find any noticeable improvements. Finally, it was the area of individual student's studying methods and attitudes that the most noticeable changes were found since the introduction of CSAT. To mention some of them, the dependency on private lessons and private academic institutes was much lessened; the learning materials were varied beside school textbooks; the students' autonomy has been increased in the area of learning need and motivations, studying strategy from memorizing to understanding, and selecting educational or occupational careers based on one's own character and talent. As a result, the introduction of CSAT seems to give student more confidence in studying and learning. Compared to these changes in individual-based studying attitudes, perceptions and learning methods connected to schooling did not change noticeably. This contrasting finding is in a sense a main point of this study. All in all, and in short, the introduction of the new College Scholastic Aptitude Test (CSAT) were somewhat effective in changing individual students' studying or learning attitudes, methods, and strategies in preparation for college entrance, but it was found to be unexpectedly ineffective in improving institutionally school organizational practices, instructional methods, guidance and disciplines, curricular implementation, and other school management and operations. This result reminds us a fact that and educational policy could not be easily rooted in the practical soil.

Aflatoxin B_1 투여가 急性 肝 病變에 미치는 영향에 對한 病理學的 硏究

장선문,이충식,강대영 충남대학교 의과대학 지역사회의학연구소 1989 충남의대잡지 Vol.16 No.1

In an attempt of elucidate the pathologic and histochemical changes of aflatoxin B_2-induced hepatie lesions, the present study in male Sprague-Dawley rats was undertaken to evalute the relation between pathologic change of the liver and histochemical changes of several enzymes : alkaline phosphatase, acid phosphatase and succinic dehydrogenase at 3. 9. 24. 48. 72, and 144 hours after single administration of aflatoxin B_1 by gastric tube. The aflatoxin B_1 was dissolved in peanut oil(0.5㎎ aflatoxin B_1 to 0.5ml peanut oil). Grouop of male rats received aflatoxin B_1 1㎎ per ㎏ of body weight, respectively. Control animals were given a similar volume of peanut oil alone. The results on morphologic and histochemical changes were as follows: 1. The necrotic change of liver was mainly periportal, and it became most severe at 24 hours and was more prominent in the large dose group than the small dose group. 2. Biliary ductular cell proliferation started to appear within 72 hours and after became regressed later in the small dose group, but it remained approximately 144 hours after exposure in the large dose group. 3. Electron microscopically, all three groups showed irregular nuclear membrane and nucleolar change characterized by segregation of granular and fibrillar elements. All the group showed cytoplasmie changes such as dilatation of rough endoplasmic reticulum with detached ribosome, hyperplasia of smooth endoplasmic reticulum, increased numbers of lipid droplets and mitochondrial alteration. The above change in the large dose group was more severe than those of the small dose group. 4. In the histochemical study of experimental animals, there was a decrease in the intensity of the staining reaction of alkaline phosphatase and succinic dehydrogenase within 24 hours and a progressive decrease in staining intensity was noted at 144 hours. And then the staining intensity of the acid phosphatase was similar to that shown by the control animal. In summary, the data obtained by present experiments indicate aflatoxin B_1 exerts periportal necrosis of hepatic lobules accompanied by bile ductular cell proliferation, and inhibition of protein synthesis, as jedged by elertron microscopic and histochemical changes.

Rat의 복강내에 투여한 5-fluorouracil-polyglycolic acid 제형이 장기에 미치는 영향에 관한 연구

강대영,송규상,최정목,노승무,정경수,오정연,김진향,양준묵,최선웅,이진호,조준식,민병무,김용백,김창식,박근성,김승영,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

For more effective intraperitoneal chemotherapy, the authers made 5-fluorouracil-polyglycolic acid composite disks(FU-PGA disks) with 5-fluorouracil and polyglycolic acid, a biodegradable polymer. We inserted the FU-PGA disk into the peritoneal cavites of Sprague-Dawley male rats, the control and three experimental groups; one FU-PGA disk insert group(300mg/kg), two FU-PGA disk insert group(600mg/kg), and three FU-PGA disk insert group(900mg/kg). The control group received a similar number of PGA disk inserts. A pharmacokinetic study was performed to measure the 5-fluorouracil concentration in the peritoneal fluid, blood, and tissues(liver, kidney and heart) at 24 hours, 72hours and 168 hours after insertion of the FU-PGA disk. Light and electron microscopic studies were done. The results were as follows: 1) The number of white blood cells and platelets decreased after FU-PGA insertion. The degree was proportional to the duration and amounts inserted. The change in the number of red blood cells varied slightly. 2) Light microscopically, slight changes were noted at 168 hours in the 3 disk insert group (900mg/kg). Mild fatty change and hepatocyte degeneration around the central veins of the liver were noted, with vacuolar degeneration in the proximal convoluted tubules of the kidney. 3) Electron microscopically,the liver showed focal increases of lipid droplets in the hepatocytes, and irregular nuclear membrane with focal nucleolar segregation of the fibrillar and granular elements. Also the double membranous structure of the hepatocytes and Kupffer cells was widened with bleb formation. The kidney showed wide separation of the nuclear double membrane in the proximal convoluted tubular cells and mesangial cells, with vacuolation and myelin figure formation in the mitochondria of the proximal convoluted tubular cells, at 72 hours and 168 hours in the 2 to 3 FU-PGA insert groups. The heart showed focal loss of cristae,vacuolation and myelin figure formation in the mitochondria of the 2 to 3 FU-PGA insert groups. In conclusion, despite the large amont of FU-PGA inserted, the histopathological changes in the liver, kidney and heart were slight, and consonant with the very low amount of 5-fluorouracil concentrations detected in the liver, kidney and heart. The above results suggest that the FU-PGA composite can serve as a new device for releasing drugs in a controlled manner and easily targeted to intraperitoneal organs. This device can improve the efficacy of intraperitoneal chemotherapy for gastric cancer.

평행봉 몸 굽혀 2회전 뒤 공중 돌아 내리기 동작의 국면별 운동학적 분석

윤창선,강대식 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.14 No.3

This thesis has an aim to examine the influence on landing of successful salto by the difference of athletic factors of salto backward tucked dismount on the parallel bars. This thesis analyzed six national representative players dividing them into the skill group (G1) who got more than 9.5 point and the unskilled group (G2) who got less than 9.5 point based on the average point by four international referees utilizing three dimensional image analyses photographed with video camera, and it got the conclusion of the athletic factors dividing into each aspect as followings. 1. As for the time spent by the groups when the thesis divided them into each aspect, G1 spent more time than G2. It's because G1 acted in stability at the moment of staying in the space and landing as it spent much time in the space with fast down swing and release, but G2 on the contrary, acted fast at the moment of space of four aspects with slow down swing and release. And its landing was unstable at the movement of low height. 2. As for the positional change in each aspect, the parallel position of G2 increased than that of G1, and the increased parallel position made the unstable salto and landing . As for the change of vertical position, at the time of down swing in the first aspect, what G1 acted at the low position of the second aspect at the high position seemed to be an act to release fast falling the high joint down, and it made salto high and made landing stable. 3. As for speed change of high joint in each aspect, G1 acted with fast horizontal speed generally at the time of release, aspect of space, and aspect of landing because of right horizontal speed at the time of down swing, and it seemed to be an act to get rotary power of double salto. As for the vertical speed, G1 acted with a much more vertical speed than G2 in four aspects with a big up-down movement by the fast vertical speed at the time of down swing and release. It means that G1 acted fast with a fast vertical speed of the high joint to get the height to stay in the air. 4. As for the change of the angle of the high joint in each aspect, G1 acted a bigger down swing and release than G2 utilizing the stretched body of the high joint at the time of down swing and release. As for change of angle of shoulder, G1 acted down swing with the shoulder joint accessed nearer than G2 to the body. At the time of down swing, it acted with a big angle of shoulder joint to stretch high shoulder at the time of swing. In addition to it, at the time of release, G2 escaped from the hand more slowly than G1 because of big angle. It made the movement of space and landing movement unstable. 5. As for change of angular speed in each aspect, G1 acted with a fast high joint down swing from the start to the first aspect. It acted with a slow speed of the angle stretching the high joint in the second and the third aspect so that it could get fast angular speed in the forth and the fifth aspect. As for the change of shoulder joint, G1 acted with a fast angular speed in the aspect of space and that of landing movement by the fast speed of shoulder joint at the time of release. In addition to it, fast angular speed of the shoulder joint in the release aspect of space made the rotary power of double salto.

A Study on the Correlation of Left Atrial Volume Change according to Left Ventricular Contraction in Atrial Fibrillation

Sung Kwan Kim,Hee Chang Chae,Choong Beom Seo,Eun Hee Seo,Chang Min Dae,Tae Eun Kim 대한CT영상기술학회 2022 대한CT영상기술학회지 Vol.24 No.1

The purpose of this study was to increase accuracy and success rate of radiofrequency catheter ablation by analysis of left atrial volume change relative to left ventricular volume change and left atrial diameter change relative to left atrial volume change. 20 patients with normal heart rhythm were set as the control group, and 20 patients with diagnosed atrial fibrillation were set as the experimental group. The cardiac cycle was divided into 10 stages ranging from 0% to 90%, and left ventricular volume, left atrial volume, left atrial diameter, pulmonary vein diameter were measured for each group. the correlation between the left ventricular volume and the left atrial volume was analyzed, and the correlation between the left atrial volume and left atrial diameter was analyzed. The diameter of the pulmonary veins was measured. As a result of analyzing the correlation between left ventricular volume and left atrial volume through Spearman correlation, the control group showed a negative correlation.(P<0.001) The experimental group were not correlated.(P=0.075) As a result of analyzing the correlation between the left atrial volume and the left atrial diameter, both groups showed a positive correlation.(P<0.001) As a result of analyzing the diameter of the pulmonary vein by Wilcoxon signed-rank test, both groups showed a significant difference in the maximum diameter and the minimum diameter.(P<0.001) Because the volume and diameter of the left atrium in patients with atrial fibrillation change irregularly, the radiologist check all cardiac cycle and reconstruct to increase the accuracy and success rate of radiofrequency catheter ablation.

TRANSIENT ISCHEMIA-INDUCED EXPRESSION AND CHANGES OF TYROSINE KINASE A IN THE HIPPOCAMPAL DENTATE GYRUS OF THE GERBIL

HWANG, IN,LEE, HYEON,YOO, KI-YEON,KIM, DAE,KIM, JUNG,KIM, CHANG,LIM, BEONG,KANG, TAE-CHEON,BANG, KYUNG,SEONG, NAK,LEE, HAK,KIM, JONG,WON, MOO Taylor Francis 2006 International journal of neuroscience Vol.116 No.8

<P>The present study examined ischemia-related changes in tyrosine kinase A (trkA) immunoreactivity and its protein content in the dentate gyrus after 5 min of transient forebrain ischemia in gerbils. One day after ischemic insult, cresyl violet-positive polymorphic cells showed ischemic degeneration. The ischemia-induced changes in trkA immunoreactivity were found in the polymorphic layer (PL) and granule cell layer (GCL) of the dentate gyrus. In the sham-operated group, trkA immunoreactivity in the dentate gyrus was very weak. From 30 min after ischemia, trkA immunoreactivity was increased in the dentate gyrus and peaked in the dentate gyrus at 12 h after ischemia-reperfusion. Thereafter, trkA immunoreactivity was decreased time-dependently after ischemia-reperfusion. Four days after ischemic insult, trkA immunoreactivity was similar to that of the sham-operated group. In addition, it was found that ischemia-related changes in trkA protein content were similar to the immunohistochemical changes. These results suggest that the chronological changes of trkA in the dentate gyrus after transient forebrain ischemia may be associated with ischemic damage in polymorphic cells of the dentate gyrus.</P>

조기 천장골염의 자기공명영상 소견

김태환 ( Tae Hwan Kim ),전재범 ( Jae Bum Jun ),심승철 ( Seung Cheol Shim ),장대국 ( Dae Kook Chang ),고회관 ( Hee Kwan Koh ),정성수 ( Sung Soo Jung ),이인홍 ( In Hong Lee ),배상철 ( Sang Cheol Bae ),유대현 ( Dae Hyun Yoo ),전의용 대한류마티스학회 1998 대한류마티스학회지 Vol.5 No.2

목적: 천장골염의 유무가 척추 관절염의 진단에 중요한데 단순 골반 검사에서 변화가 없는 환자를 대상으로 MRI를 이용하여 천장골염의 조기변화 소견 및 MRI방법에 따른 장점을 비교하고자 하였다. 대상 및 방법: 단순 골반 검사에서 천장골염 유무가 확실하게 구분되지 않은 혈청 음성 척추 관절염 환자 26명을 대상으로 MRI를 시행하고 염증의 주침범위치를 천측과 장측, 관절의 상하로 구분하고, MRI방법에 따른 변화를 비교하였다. 결과: 모든 예에서 조영 증강되는 판누스를 관찰할 수 있었고, Grade I 이하에서는 장골측과 관절하부, 인대성 관절보다 활막성 관절을 더 많이 침범하였다. Grade II 이상에서도 장골측과 관절 하부에 더 많았으나 인대성 관절을 Grade I이하에서보다 더 많이 침범하였다. 관절 주변 지방 침착역시 장골측과 관절 하부에 더 주로 침범하였고 Grade II 이상에서 약간 더 많았다. 관절 주변 골염은 Grade 0에서는 없었고, Grade I에서는 주로 장골측과 관절 하부에서 92%가 양성이었고, Grade II에서는 93%에서, Grade III에서는 64%에서 양성으로, 장골측을 주로 침범하였으나 관절 상하부의 구분은 없었다. 인대성 천장골 관절은 Grade I 이하에서 38%, II 이상에서는 94%에서 침범하였다. 관절 주변 골염과 지방 침착, 그리고 판누스의 관찰에는 MPGR보다 스핀에코 영상이 좋았고, 관절면의 불규칙성 또는 관절강의 확대와 관절 강직여부의 관찰에는 스핀에코에 비해 MPGR 영상이 좋았고, 연골하 경화는 비슷하였다. 천장골염의 정도와 ESR, CRP와의 연관성은 없었다. 걸론: 천장골 관절에서 염증의 시작은 주로 장골 측과 관절의 하부에서 먼저 시작되고, 관절이 진행될수록 장골측에서 천골측까지로 범위가 확대 되었다. MRI방법에 의한 차이로 초기단계에는 스핀에코 영상이 관절염을 확인하는데 도움이 되고 관절면이 불규칙하게 되고 경화가 되어 병이 진행된 상태에서는 MPGR영상이 진단에 더 도움이 되었다. 염증성 배부 동통이 있는 경우 단순 골반 검사에서 이상이 없는 환자인 경우에도 MRI 검사를 시행하여 천장골염의 유무를 확인하는 것이 중요하다. Objective: The early detection of sacroiliitis on X-ray is important to diagnose spondyloarthropathy(SpA). The conventional radiography, bone scan, and computer tomogram have the problems of sensitivity, specificity, and side effects. We examined sacroiliitis using MR imaging in patients who had inflammatory back pain, but no definite changes in conventional radiogrphy. Other radiologic techniques were compared in detection of early sacroillitis. Methods: Twenty six patients with SpA were examined. The MRI findings of both sacroiliac joints were evaluated in every patients, such as pannus, periarticular osteitis and fat accumulation, subchondral sclerosis, and joint space changes(irregularity, ankylosis). Also we analyzed the changes of sacroiliac joints in sacroiliitis. Results: The predominant sites of involvement were upper aspect and iliac surface of sacroiliac joint in subchondral sclerosis, lower and iliac in pannus, periarticular fat accumulation, and iliac in periarticular osteitis. The MPGR images were superior to spin echo images in evaluation of joint space changes(irregularity, and ankylosis). Conclusions: Sacroiliitis is initiated in iliac side and lower portion of sacroiliac joints. MRI can detect early changes of sacroiliitis in patients with no conventional radiographic changes. MRI seems to be needed in patients with inflammatory back pain.

High-Resolution Capacitive Microinclinometer With Oblique Comb Electrodes Using (110) Silicon

Dae-Hun Jeong,Sung-Sik Yun,Byung-Geun Lee,Myung-Lae Lee,Chang-Auk Choi,Jong-Hyun Lee IEEE 2011 Journal of microelectromechanical systems Vol.20 No.6

<P>We propose a new capacitive microinclinometer where oblique comb electrodes and double-folded suspension springs are aligned parallel to the vertical (111) plane of (110) silicon. The oblique comb utilizes both the overlapped area and the gap between movable and stationary electrodes, resulting in a considerable increase in sensitivity (capacitance change/angle). The resolution becomes even higher by taking advantage of the smooth (111) sidewalls of the oblique comb electrodes, which are fabricated using silicon deep reactive ion etching followed by crystalline wet etching. The surface roughness was reduced from 200 (R<SUB>rms</SUB>) to 20 nm (R<SUB>rms</SUB>), and the verticality was improved from 88.7° to 89.7°. The capacitance change of the fabricated inclinometer experimentally ranges from -0.793 to 0.783 pF for the full range of inclination angle (from -90° to 90°). The estimated worst resolution, which is obtainable at an inclination angle of ±85°, was as low as 0.25°.</P>

In Vitro Transport of Fexofenadine HCl in Deformable Liposomes Across the Human Nasal Epithelial Cell Monolayers

Dae-Duk Kim,Hongxia Lin,Chi-Ho Lee,Chang-Koo Shim,Suk-Jae Chung 한국약제학회 2004 Journal of Pharmaceutical Investigation Vol.34 No.6

Fexofenadine • HCl is non-sedating histamine H1 receptor antagonist that can be used for the treatment of seasonal allergic rhinitis. The objective of this study was to investigate whether the carriers of deformable liposomes can enhance the transepithelial permeability of fexofenadine • HCl across the in vitro ALI human nasal monolayer model. Characterization of this model was achieved by bioelectric measurements and morphological studies. The passage 2 and 3 of cell monolayers exhibited the TEER value of 2852482 ohm´cm2 on 11 days of seeding and maintained high TEER value for 5 days. The deformable liposome of fexofenadine • HCl was prepared with phosphatidylcholine (PC) and cholic acid using extruder method. The mean particle size was about 200 nm and the maximum entrapment efficiency of 33.0% was obtained in the formulation of 1% PC and 100 mg/ml fexofenadine • HCl. The toxicity of the deformable liposome to human nasal monolayers was evaluated by MTT assay and TEER value change. MTT assay showed that it has no toxic effect on the nasal epithelial cells in 2-hour incubation when the PC concentration was below 1%. However, deformable liposome could not enhance the transepithelial permeability (Papp) and cellular uptake of fexofenadine • HCl. In conclusion, the in vitro model could be used in nasal drug transport studies and evaluation of transepithelial permeability of formulations.